/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. Copyright (c) 2008, 2015, MariaDB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ /** @file @brief Sum functions (COUNT, MIN...) */ #ifdef USE_PRAGMA_IMPLEMENTATION #pragma implementation // gcc: Class implementation #endif #include #include "sql_priv.h" #include "sql_select.h" #include "uniques.h" /** Calculate the affordable RAM limit for structures like TREE or Unique used in Item_sum_* */ ulonglong Item_sum::ram_limitation(THD *thd) { return MY_MIN(thd->variables.tmp_table_size, thd->variables.max_heap_table_size); } /** Prepare an aggregate function item for checking context conditions. The function initializes the members of the Item_sum object created for a set function that are used to check validity of the set function occurrence. If the set function is not allowed in any subquery where it occurs an error is reported immediately. @param thd reference to the thread context info @note This function is to be called for any item created for a set function object when the traversal of trees built for expressions used in the query is performed at the phase of context analysis. This function is to be invoked at the descent of this traversal. @retval TRUE if an error is reported @retval FALSE otherwise */ bool Item_sum::init_sum_func_check(THD *thd) { SELECT_LEX *curr_sel= thd->lex->current_select; if (!curr_sel->name_visibility_map) { for (SELECT_LEX *sl= curr_sel; sl; sl= sl->context.outer_select()) { curr_sel->name_visibility_map|= (1 << sl-> nest_level); } } if (!(thd->lex->allow_sum_func & curr_sel->name_visibility_map)) { my_message(ER_INVALID_GROUP_FUNC_USE, ER_THD(thd, ER_INVALID_GROUP_FUNC_USE), MYF(0)); return TRUE; } /* Set a reference to the nesting set function if there is any */ in_sum_func= thd->lex->in_sum_func; /* Save a pointer to object to be used in items for nested set functions */ thd->lex->in_sum_func= this; nest_level= thd->lex->current_select->nest_level; ref_by= 0; aggr_level= -1; aggr_sel= NULL; max_arg_level= -1; max_sum_func_level= -1; outer_fields.empty(); return FALSE; } /** Check constraints imposed on a usage of a set function. The method verifies whether context conditions imposed on a usage of any set function are met for this occurrence. It checks whether the set function occurs in the position where it can be aggregated and, when it happens to occur in argument of another set function, the method checks that these two functions are aggregated in different subqueries. If the context conditions are not met the method reports an error. If the set function is aggregated in some outer subquery the method adds it to the chain of items for such set functions that is attached to the the st_select_lex structure for this subquery. A number of designated members of the object are used to check the conditions. They are specified in the comment before the Item_sum class declaration. Additionally a bitmap variable called allow_sum_func is employed. It is included into the thd->lex structure. The bitmap contains 1 at n-th position if the set function happens to occur under a construct of the n-th level subquery where usage of set functions are allowed (i.e either in the SELECT list or in the HAVING clause of the corresponding subquery) Consider the query: @code SELECT SUM(t1.b) FROM t1 GROUP BY t1.a HAVING t1.a IN (SELECT t2.c FROM t2 WHERE AVG(t1.b) > 20) AND t1.a > (SELECT MIN(t2.d) FROM t2); @endcode allow_sum_func will contain: - for SUM(t1.b) - 1 at the first position - for AVG(t1.b) - 1 at the first position, 0 at the second position - for MIN(t2.d) - 1 at the first position, 1 at the second position. @param thd reference to the thread context info @param ref location of the pointer to this item in the embedding expression @note This function is to be called for any item created for a set function object when the traversal of trees built for expressions used in the query is performed at the phase of context analysis. This function is to be invoked at the ascent of this traversal. @retval TRUE if an error is reported @retval FALSE otherwise */ bool Item_sum::check_sum_func(THD *thd, Item **ref) { SELECT_LEX *curr_sel= thd->lex->current_select; nesting_map allow_sum_func= (thd->lex->allow_sum_func & curr_sel->name_visibility_map); bool invalid= FALSE; DBUG_ASSERT(curr_sel->name_visibility_map); // should be set already if (window_func_sum_expr_flag) return false; /* The value of max_arg_level is updated if an argument of the set function contains a column reference resolved against a subquery whose level is greater than the current value of max_arg_level. max_arg_level cannot be greater than nest level. nest level is always >= 0 */ if (nest_level == max_arg_level) { /* The function must be aggregated in the current subquery, If it is there under a construct where it is not allowed we report an error. */ invalid= !(allow_sum_func & ((nesting_map)1 << max_arg_level)); } else if (max_arg_level >= 0 || !(allow_sum_func & ((nesting_map)1 << nest_level))) { /* The set function can be aggregated only in outer subqueries. Try to find a subquery where it can be aggregated; If we fail to find such a subquery report an error. */ if (register_sum_func(thd, ref)) return TRUE; invalid= aggr_level < 0 && !(allow_sum_func & ((nesting_map)1 << nest_level)); if (!invalid && thd->variables.sql_mode & MODE_ANSI) invalid= aggr_level < 0 && max_arg_level < nest_level; } if (!invalid && aggr_level < 0) { aggr_level= nest_level; aggr_sel= curr_sel; } /* By this moment we either found a subquery where the set function is to be aggregated and assigned a value that is >= 0 to aggr_level, or set the value of 'invalid' to TRUE to report later an error. */ /* Additionally we have to check whether possible nested set functions are acceptable here: they are not, if the level of aggregation of some of them is less than aggr_level. */ if (!invalid) invalid= aggr_level <= max_sum_func_level; if (invalid) { my_message(ER_INVALID_GROUP_FUNC_USE, ER_THD(thd, ER_INVALID_GROUP_FUNC_USE), MYF(0)); return TRUE; } if (in_sum_func) { /* If the set function is nested adjust the value of max_sum_func_level for the nesting set function. We take into account only enclosed set functions that are to be aggregated on the same level or above of the nest level of the enclosing set function. But we must always pass up the max_sum_func_level because it is the maximum nested level of all directly and indirectly enclosed set functions. We must do that even for set functions that are aggregated inside of their enclosing set function's nest level because the enclosing function may contain another enclosing function that is to be aggregated outside or on the same level as its parent's nest level. */ if (in_sum_func->nest_level >= aggr_level) set_if_bigger(in_sum_func->max_sum_func_level, aggr_level); set_if_bigger(in_sum_func->max_sum_func_level, max_sum_func_level); } /* Check that non-aggregated fields and sum functions aren't mixed in the same select in the ONLY_FULL_GROUP_BY mode. */ if (outer_fields.elements) { Item_field *field; /* Here we compare the nesting level of the select to which an outer field belongs to with the aggregation level of the sum function. All fields in the outer_fields list are checked. If the nesting level is equal to the aggregation level then the field is aggregated by this sum function. If the nesting level is less than the aggregation level then the field belongs to an outer select. In this case if there is an embedding sum function add current field to functions outer_fields list. If there is no embedding function then the current field treated as non aggregated and the select it belongs to is marked accordingly. If the nesting level is greater than the aggregation level then it means that this field was added by an inner sum function. Consider an example: select avg ( <-- we are here, checking outer.f1 select ( select sum(outer.f1 + inner.f1) from inner ) from outer) from most_outer; In this case we check that no aggregate functions are used in the select the field belongs to. If there are some then an error is raised. */ List_iterator of(outer_fields); while ((field= of++)) { SELECT_LEX *sel= field->field->table->pos_in_table_list->select_lex; if (sel->nest_level < aggr_level) { if (in_sum_func) { /* Let upper function decide whether this field is a non aggregated one. */ in_sum_func->outer_fields.push_back(field, thd->mem_root); } else sel->set_non_agg_field_used(true); } if (sel->nest_level > aggr_level && (sel->agg_func_used()) && !sel->group_list.elements) { my_message(ER_MIX_OF_GROUP_FUNC_AND_FIELDS, ER_THD(thd, ER_MIX_OF_GROUP_FUNC_AND_FIELDS), MYF(0)); return TRUE; } } } aggr_sel->set_agg_func_used(true); update_used_tables(); thd->lex->in_sum_func= in_sum_func; return FALSE; } /** Attach a set function to the subquery where it must be aggregated. The function looks for an outer subquery where the set function must be aggregated. If it finds such a subquery then aggr_level is set to the nest level of this subquery and the item for the set function is added to the list of set functions used in nested subqueries inner_sum_func_list defined for each subquery. When the item is placed there the field 'ref_by' is set to ref. @note Now we 'register' only set functions that are aggregated in outer subqueries. Actually it makes sense to link all set function for a subquery in one chain. It would simplify the process of 'splitting' for set functions. @param thd reference to the thread context info @param ref location of the pointer to this item in the embedding expression @retval FALSE if the executes without failures (currently always) @retval TRUE otherwise */ bool Item_sum::register_sum_func(THD *thd, Item **ref) { SELECT_LEX *sl; nesting_map allow_sum_func= thd->lex->allow_sum_func; for (sl= thd->lex->current_select->context.outer_select() ; sl && sl->nest_level > max_arg_level; sl= sl->context.outer_select()) { if (aggr_level < 0 && (allow_sum_func & ((nesting_map)1 << sl->nest_level))) { /* Found the most nested subquery where the function can be aggregated */ aggr_level= sl->nest_level; aggr_sel= sl; } } if (sl && (allow_sum_func & ((nesting_map)1 << sl->nest_level))) { /* We reached the subquery of level max_arg_level and checked that the function can be aggregated here. The set function will be aggregated in this subquery. */ aggr_level= sl->nest_level; aggr_sel= sl; } if (aggr_level >= 0) { ref_by= ref; /* Add the object to the list of registered objects assigned to aggr_sel */ if (!aggr_sel->inner_sum_func_list) next= this; else { next= aggr_sel->inner_sum_func_list->next; aggr_sel->inner_sum_func_list->next= this; } aggr_sel->inner_sum_func_list= this; aggr_sel->with_sum_func= 1; /* Mark Item_subselect(s) as containing aggregate function all the way up to aggregate function's calculation context. Note that we must not mark the Item of calculation context itself because with_sum_func on the calculation context st_select_lex is already set above. with_sum_func being set for an Item means that this Item refers (somewhere in it, e.g. one of its arguments if it's a function) directly or through intermediate items to an aggregate function that is calculated in a context "outside" of the Item (e.g. in the current or outer select). with_sum_func being set for an st_select_lex means that this st_select_lex has aggregate functions directly referenced (i.e. not through a sub-select). */ for (sl= thd->lex->current_select; sl && sl != aggr_sel && sl->master_unit()->item; sl= sl->master_unit()->outer_select() ) sl->master_unit()->item->with_sum_func= 1; } thd->lex->current_select->mark_as_dependent(thd, aggr_sel, NULL); if ((thd->lex->describe & DESCRIBE_EXTENDED) && aggr_sel) { push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE, ER_WARN_AGGFUNC_DEPENDENCE, ER_THD(thd, ER_WARN_AGGFUNC_DEPENDENCE), func_name(), thd->lex->current_select->select_number, aggr_sel->select_number); } return FALSE; } bool Item_sum::collect_outer_ref_processor(void *param) { Collect_deps_prm *prm= (Collect_deps_prm *)param; SELECT_LEX *ds; if ((ds= depended_from()) && ds->nest_level_base == prm->nest_level_base && ds->nest_level < prm->nest_level) { if (prm->collect) prm->parameters->add_unique(this, &cmp_items); else prm->count++; } return FALSE; } Item_sum::Item_sum(THD *thd, List &list): Item_func_or_sum(thd, list) { if (!(orig_args= (Item **) thd->alloc(sizeof(Item *) * arg_count))) { args= NULL; } mark_as_sum_func(); init_aggregator(); list.empty(); // Fields are used } /** Constructor used in processing select with temporary tebles. */ Item_sum::Item_sum(THD *thd, Item_sum *item): Item_func_or_sum(thd, item), aggr_sel(item->aggr_sel), nest_level(item->nest_level), aggr_level(item->aggr_level), quick_group(item->quick_group), orig_args(NULL) { if (arg_count <= 2) { orig_args=tmp_orig_args; } else { if (!(orig_args= (Item**) thd->alloc(sizeof(Item*)*arg_count))) return; } memcpy(orig_args, item->orig_args, sizeof(Item*)*arg_count); init_aggregator(); with_distinct= item->with_distinct; if (item->aggr) set_aggregator(item->aggr->Aggrtype()); } void Item_sum::mark_as_sum_func() { SELECT_LEX *cur_select= current_thd->lex->current_select; cur_select->n_sum_items++; cur_select->with_sum_func= 1; const_item_cache= false; with_sum_func= 1; with_field= 0; window_func_sum_expr_flag= false; } void Item_sum::print(String *str, enum_query_type query_type) { /* orig_args is not filled with valid values until fix_fields() */ Item **pargs= fixed ? orig_args : args; str->append(func_name()); /* TODO: The fact that func_name() may return a name with an extra '(' is really annoying. This shoud be fixed. */ if (!is_aggr_sum_func()) str->append('('); for (uint i=0 ; i < arg_count ; i++) { if (i) str->append(','); pargs[i]->print(str, query_type); } str->append(')'); } void Item_sum::fix_num_length_and_dec() { decimals=0; for (uint i=0 ; i < arg_count ; i++) set_if_bigger(decimals,args[i]->decimals); max_length=float_length(decimals); } Item *Item_sum::get_tmp_table_item(THD *thd) { Item_sum* sum_item= (Item_sum *) copy_or_same(thd); if (sum_item && sum_item->result_field) // If not a const sum func { Field *result_field_tmp= sum_item->result_field; for (uint i=0 ; i < sum_item->arg_count ; i++) { Item *arg= sum_item->args[i]; if (!arg->const_item()) { if (arg->type() == Item::FIELD_ITEM) ((Item_field*) arg)->field= result_field_tmp++; else sum_item->args[i]= new (thd->mem_root) Item_temptable_field(thd, result_field_tmp++); } } } return sum_item; } void Item_sum::update_used_tables () { if (!Item_sum::const_item()) { used_tables_cache= 0; for (uint i=0 ; i < arg_count ; i++) { args[i]->update_used_tables(); used_tables_cache|= args[i]->used_tables(); } /* MariaDB: don't run the following { used_tables_cache&= PSEUDO_TABLE_BITS; // the aggregate function is aggregated into its local context used_tables_cache|= ((table_map)1 << aggr_sel->join->tables) - 1; } because if we do it, table elimination will assume that - constructs like "COUNT(*)" use columns from all tables - so, it is not possible to eliminate any table our solution for COUNT(*) is that it has item->used_tables() == 0 && !item->const_item() */ } } Item *Item_sum::set_arg(uint i, THD *thd, Item *new_val) { thd->change_item_tree(args + i, new_val); return new_val; } int Item_sum::set_aggregator(Aggregator::Aggregator_type aggregator) { /* Dependent subselects may be executed multiple times, making set_aggregator to be called multiple times. The aggregator type will be the same, but it needs to be reset so that it is reevaluated with the new dependent data. This function may also be called multiple times during query optimization. In this case, the type may change, so we delete the old aggregator, and create a new one. */ if (aggr && aggregator == aggr->Aggrtype()) { aggr->clear(); return FALSE; } delete aggr; switch (aggregator) { case Aggregator::DISTINCT_AGGREGATOR: aggr= new Aggregator_distinct(this); break; case Aggregator::SIMPLE_AGGREGATOR: aggr= new Aggregator_simple(this); break; }; return aggr ? FALSE : TRUE; } void Item_sum::cleanup() { if (aggr) { delete aggr; aggr= NULL; } Item_result_field::cleanup(); const_item_cache= false; } Item *Item_sum::result_item(THD *thd, Field *field) { return new (thd->mem_root) Item_field(thd, field); } bool Item_sum::check_vcol_func_processor(void *arg) { return mark_unsupported_function(func_name(), is_aggr_sum_func() ? ")" : "()", arg, VCOL_IMPOSSIBLE); } /** Compare keys consisting of single field that cannot be compared as binary. Used by the Unique class to compare keys. Will do correct comparisons for all field types. @param arg Pointer to the relevant Field class instance @param key1 left key image @param key2 right key image @return comparison result @retval < 0 if key1 < key2 @retval = 0 if key1 = key2 @retval > 0 if key1 > key2 */ int simple_str_key_cmp(void* arg, uchar* key1, uchar* key2) { Field *f= (Field*) arg; return f->cmp(key1, key2); } C_MODE_START int count_distinct_walk(void *elem, element_count count, void *arg) { (*((ulonglong*)arg))++; return 0; } C_MODE_END /** Correctly compare composite keys. Used by the Unique class to compare keys. Will do correct comparisons for composite keys with various field types. @param arg Pointer to the relevant Aggregator_distinct instance @param key1 left key image @param key2 right key image @return comparison result @retval <0 if key1 < key2 @retval =0 if key1 = key2 @retval >0 if key1 > key2 */ int Aggregator_distinct::composite_key_cmp(void* arg, uchar* key1, uchar* key2) { Aggregator_distinct *aggr= (Aggregator_distinct *) arg; Field **field = aggr->table->field; Field **field_end= field + aggr->table->s->fields; uint32 *lengths=aggr->field_lengths; for (; field < field_end; ++field) { Field* f = *field; int len = *lengths++; int res = f->cmp(key1, key2); if (res) return res; key1 += len; key2 += len; } return 0; } /***************************************************************************/ C_MODE_START /* Declarations for auxilary C-callbacks */ int simple_raw_key_cmp(void* arg, const void* key1, const void* key2) { return memcmp(key1, key2, *(uint *) arg); } static int item_sum_distinct_walk_for_count(void *element, element_count num_of_dups, void *item) { return ((Aggregator_distinct*) (item))->unique_walk_function_for_count(element); } static int item_sum_distinct_walk(void *element, element_count num_of_dups, void *item) { return ((Aggregator_distinct*) (item))->unique_walk_function(element); } C_MODE_END /***************************************************************************/ /** Called before feeding the first row. Used to allocate/setup the internal structures used for aggregation. @param thd Thread descriptor @return status @retval FALSE success @retval TRUE faliure Prepares Aggregator_distinct to process the incoming stream. Creates the temporary table and the Unique class if needed. Called by Item_sum::aggregator_setup() */ bool Aggregator_distinct::setup(THD *thd) { endup_done= FALSE; /* Setup can be called twice for ROLLUP items. This is a bug. Please add DBUG_ASSERT(tree == 0) here when it's fixed. */ if (tree || table || tmp_table_param) return FALSE; if (item_sum->setup(thd)) return TRUE; if (item_sum->sum_func() == Item_sum::COUNT_FUNC || item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC) { List list; SELECT_LEX *select_lex= thd->lex->current_select; if (!(tmp_table_param= new TMP_TABLE_PARAM)) return TRUE; /* Create a table with an unique key over all parameters */ for (uint i=0; i < item_sum->get_arg_count() ; i++) { Item *item=item_sum->get_arg(i); if (list.push_back(item, thd->mem_root)) return TRUE; // End of memory if (item->const_item() && item->is_null()) always_null= true; } if (always_null) return FALSE; count_field_types(select_lex, tmp_table_param, list, 0); tmp_table_param->force_copy_fields= item_sum->has_force_copy_fields(); DBUG_ASSERT(table == 0); /* Make create_tmp_table() convert BIT columns to BIGINT. This is needed because BIT fields store parts of their data in table's null bits, and we don't have methods to compare two table records, which is needed by Unique which is used when HEAP table is used. */ { List_iterator_fast li(list); Item *item; while ((item= li++)) { if (item->type() == Item::FIELD_ITEM && ((Item_field*)item)->field->type() == FIELD_TYPE_BIT) item->marker=4; } } if (!(table= create_tmp_table(thd, tmp_table_param, list, (ORDER*) 0, 1, 0, (select_lex->options | thd->variables.option_bits), HA_POS_ERROR, const_cast("")))) return TRUE; table->file->extra(HA_EXTRA_NO_ROWS); // Don't update rows table->no_rows=1; if (table->s->db_type() == heap_hton) { /* No blobs, otherwise it would have been MyISAM: set up a compare function and its arguments to use with Unique. */ qsort_cmp2 compare_key; void* cmp_arg; Field **field= table->field; Field **field_end= field + table->s->fields; bool all_binary= TRUE; for (tree_key_length= 0; field < field_end; ++field) { Field *f= *field; enum enum_field_types type= f->type(); tree_key_length+= f->pack_length(); if ((type == MYSQL_TYPE_VARCHAR) || (!f->binary() && (type == MYSQL_TYPE_STRING || type == MYSQL_TYPE_VAR_STRING))) { all_binary= FALSE; break; } } if (all_binary) { cmp_arg= (void*) &tree_key_length; compare_key= (qsort_cmp2) simple_raw_key_cmp; } else { if (table->s->fields == 1) { /* If we have only one field, which is the most common use of count(distinct), it is much faster to use a simpler key compare method that can take advantage of not having to worry about other fields. */ compare_key= (qsort_cmp2) simple_str_key_cmp; cmp_arg= (void*) table->field[0]; /* tree_key_length has been set already */ } else { uint32 *length; compare_key= (qsort_cmp2) composite_key_cmp; cmp_arg= (void*) this; field_lengths= (uint32*) thd->alloc(table->s->fields * sizeof(uint32)); for (tree_key_length= 0, length= field_lengths, field= table->field; field < field_end; ++field, ++length) { *length= (*field)->pack_length(); tree_key_length+= *length; } } } DBUG_ASSERT(tree == 0); tree= new Unique(compare_key, cmp_arg, tree_key_length, item_sum->ram_limitation(thd)); /* The only time tree_key_length could be 0 is if someone does count(distinct) on a char(0) field - stupid thing to do, but this has to be handled - otherwise someone can crash the server with a DoS attack */ if (! tree) return TRUE; } return FALSE; } else { Item *arg; DBUG_ENTER("Aggregator_distinct::setup"); /* It's legal to call setup() more than once when in a subquery */ if (tree) DBUG_RETURN(FALSE); /* Virtual table and the tree are created anew on each re-execution of PS/SP. Hence all further allocations are performed in the runtime mem_root. */ item_sum->null_value= item_sum->maybe_null= 1; item_sum->quick_group= 0; DBUG_ASSERT(item_sum->get_arg(0)->fixed); arg= item_sum->get_arg(0); if (arg->const_item()) { (void) arg->is_null(); if (arg->null_value) always_null= true; } if (always_null) DBUG_RETURN(FALSE); Field *field= arg->make_num_distinct_aggregator_field(thd->mem_root, arg); if (!field || !(table= create_virtual_tmp_table(thd, field))) DBUG_RETURN(TRUE); /* XXX: check that the case of CHAR(0) works OK */ tree_key_length= table->s->reclength - table->s->null_bytes; /* Unique handles all unique elements in a tree until they can't fit in. Then the tree is dumped to the temporary file. We can use simple_raw_key_cmp because the table contains numbers only; decimals are converted to binary representation as well. */ tree= new Unique(simple_raw_key_cmp, &tree_key_length, tree_key_length, item_sum->ram_limitation(thd)); DBUG_RETURN(tree == 0); } } /** Invalidate calculated value and clear the distinct rows. Frees space used by the internal data structures. Removes the accumulated distinct rows. Invalidates the calculated result. */ void Aggregator_distinct::clear() { endup_done= FALSE; item_sum->clear(); if (tree) tree->reset(); /* tree and table can be both null only if always_null */ if (item_sum->sum_func() == Item_sum::COUNT_FUNC || item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC) { if (!tree && table) { table->file->extra(HA_EXTRA_NO_CACHE); table->file->ha_delete_all_rows(); table->file->extra(HA_EXTRA_WRITE_CACHE); } } else { item_sum->null_value= 1; } } /** Process incoming row. Add it to Unique/temp hash table if it's unique. Skip the row if not unique. Prepare Aggregator_distinct to process the incoming stream. Create the temporary table and the Unique class if needed. Called by Item_sum::aggregator_add(). To actually get the result value in item_sum's buffers Aggregator_distinct::endup() must be called. @return status @retval FALSE success @retval TRUE failure */ bool Aggregator_distinct::add() { if (always_null) return 0; if (item_sum->sum_func() == Item_sum::COUNT_FUNC || item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC) { int error; copy_fields(tmp_table_param); if (copy_funcs(tmp_table_param->items_to_copy, table->in_use)) return TRUE; for (Field **field=table->field ; *field ; field++) if ((*field)->is_real_null(0)) return 0; // Don't count NULL if (tree) { /* The first few bytes of record (at least one) are just markers for deleted and NULLs. We want to skip them since they will bloat the tree without providing any valuable info. Besides, key_length used to initialize the tree didn't include space for them. */ return tree->unique_add(table->record[0] + table->s->null_bytes); } if ((error= table->file->ha_write_tmp_row(table->record[0])) && table->file->is_fatal_error(error, HA_CHECK_DUP)) return TRUE; return FALSE; } else { item_sum->get_arg(0)->save_in_field(table->field[0], FALSE); if (table->field[0]->is_null()) return 0; DBUG_ASSERT(tree); item_sum->null_value= 0; /* '0' values are also stored in the tree. This doesn't matter for SUM(DISTINCT), but is important for AVG(DISTINCT) */ return tree->unique_add(table->field[0]->ptr); } } /** Calculate the aggregate function value. Since Distinct_aggregator::add() just collects the distinct rows, we must go over the distinct rows and feed them to the aggregation function before returning its value. This is what endup () does. It also sets the result validity flag endup_done to TRUE so it will not recalculate the aggregate value again if the Item_sum hasn't been reset. */ void Aggregator_distinct::endup() { /* prevent consecutive recalculations */ if (endup_done) return; /* we are going to calculate the aggregate value afresh */ item_sum->clear(); /* The result will definitely be null : no more calculations needed */ if (always_null) return; if (item_sum->sum_func() == Item_sum::COUNT_FUNC || item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC) { DBUG_ASSERT(item_sum->fixed == 1); Item_sum_count *sum= (Item_sum_count *)item_sum; if (tree && tree->elements == 0) { /* everything fits in memory */ sum->count= (longlong) tree->elements_in_tree(); endup_done= TRUE; } if (!tree) { /* there were blobs */ table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK); sum->count= table->file->stats.records; endup_done= TRUE; } } /* We don't have a tree only if 'setup()' hasn't been called; this is the case of sql_executor.cc:return_zero_rows. */ if (tree && !endup_done) { /* All tree's values are not NULL. Note that value of field is changed as we walk the tree, in Aggregator_distinct::unique_walk_function, but it's always not NULL. */ table->field[0]->set_notnull(); /* go over the tree of distinct keys and calculate the aggregate value */ use_distinct_values= TRUE; tree_walk_action func; if (item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC) func= item_sum_distinct_walk_for_count; else func= item_sum_distinct_walk; tree->walk(table, func, (void*) this); use_distinct_values= FALSE; } /* prevent consecutive recalculations */ endup_done= TRUE; } String * Item_sum_num::val_str(String *str) { return val_string_from_real(str); } my_decimal *Item_sum_num::val_decimal(my_decimal *decimal_value) { return val_decimal_from_real(decimal_value); } String * Item_sum_int::val_str(String *str) { return val_string_from_int(str); } my_decimal *Item_sum_int::val_decimal(my_decimal *decimal_value) { return val_decimal_from_int(decimal_value); } bool Item_sum_num::fix_fields(THD *thd, Item **ref) { DBUG_ASSERT(fixed == 0); if (init_sum_func_check(thd)) return TRUE; decimals=0; maybe_null= sum_func() != COUNT_FUNC; for (uint i=0 ; i < arg_count ; i++) { if (args[i]->fix_fields(thd, args + i) || args[i]->check_cols(1)) return TRUE; set_if_bigger(decimals, args[i]->decimals); with_subselect|= args[i]->with_subselect; } result_field=0; max_length=float_length(decimals); null_value=1; fix_length_and_dec(); if (check_sum_func(thd, ref)) return TRUE; memcpy (orig_args, args, sizeof (Item *) * arg_count); fixed= 1; return FALSE; } bool Item_sum_hybrid::fix_fields(THD *thd, Item **ref) { DBUG_ASSERT(fixed == 0); Item *item= args[0]; if (init_sum_func_check(thd)) return TRUE; // 'item' can be changed during fix_fields if ((!item->fixed && item->fix_fields(thd, args)) || (item= args[0])->check_cols(1)) return TRUE; Type_std_attributes::set(args[0]); with_subselect= args[0]->with_subselect; Item *item2= item->real_item(); if (item2->type() == Item::FIELD_ITEM) set_handler_by_field_type(((Item_field*) item2)->field->type()); else if (item->cmp_type() == TIME_RESULT) set_handler_by_field_type(item2->field_type()); else set_handler_by_result_type(item2->result_type(), max_length, collation.collation); switch (Item_sum_hybrid::result_type()) { case INT_RESULT: case DECIMAL_RESULT: case STRING_RESULT: break; case REAL_RESULT: max_length= float_length(decimals); break; case ROW_RESULT: case TIME_RESULT: DBUG_ASSERT(0); }; if (!is_window_func_sum_expr()) setup_hybrid(thd, args[0], NULL); /* MIN/MAX can return NULL for empty set indepedent of the used column */ maybe_null= 1; result_field=0; null_value=1; fix_length_and_dec(); if (check_sum_func(thd, ref)) return TRUE; orig_args[0]= args[0]; fixed= 1; return FALSE; } /** MIN/MAX function setup. @param item argument of MIN/MAX function @param value_arg calculated value of MIN/MAX function @details Setup cache/comparator of MIN/MAX functions. When called by the copy_or_same function value_arg parameter contains calculated value of the original MIN/MAX object and it is saved in this object's cache. We mark the value and arg_cache with 'RAND_TABLE_BIT' to ensure that Arg_comparator::compare_datetime() doesn't allocate new item inside of Arg_comparator. This would cause compare_datetime() and Item_sum_min::add() to use different values! */ void Item_sum_hybrid::setup_hybrid(THD *thd, Item *item, Item *value_arg) { if (!(value= Item_cache::get_cache(thd, item, item->cmp_type()))) return; value->setup(thd, item); value->store(value_arg); /* Don't cache value, as it will change */ if (!item->const_item()) value->set_used_tables(RAND_TABLE_BIT); if (!(arg_cache= Item_cache::get_cache(thd, item, item->cmp_type()))) return; arg_cache->setup(thd, item); /* Don't cache value, as it will change */ if (!item->const_item()) arg_cache->set_used_tables(RAND_TABLE_BIT); cmp= new Arg_comparator(); if (cmp) cmp->set_cmp_func(this, (Item**)&arg_cache, (Item**)&value, FALSE); collation.set(item->collation); } Field *Item_sum_hybrid::create_tmp_field(bool group, TABLE *table) { Field *field; MEM_ROOT *mem_root; if (args[0]->type() == Item::FIELD_ITEM) { field= ((Item_field*) args[0])->field; if ((field= create_tmp_field_from_field(table->in_use, field, name, table, NULL))) field->flags&= ~NOT_NULL_FLAG; return field; } /* DATE/TIME fields have STRING_RESULT result types. In order to preserve field type, it's needed to handle DATE/TIME fields creations separately. */ mem_root= table->in_use->mem_root; switch (args[0]->field_type()) { case MYSQL_TYPE_DATE: field= new (mem_root) Field_newdate(0, maybe_null ? (uchar*)"" : 0, 0, Field::NONE, name); break; case MYSQL_TYPE_TIME: field= new_Field_time(mem_root, 0, maybe_null ? (uchar*)"" : 0, 0, Field::NONE, name, decimals); break; case MYSQL_TYPE_TIMESTAMP: case MYSQL_TYPE_DATETIME: field= new_Field_datetime(mem_root, 0, maybe_null ? (uchar*)"" : 0, 0, Field::NONE, name, decimals); break; default: return Item_sum::create_tmp_field(group, table); } if (field) field->init(table); return field; } /*********************************************************************** ** reset and add of sum_func ***********************************************************************/ /** @todo check if the following assignments are really needed */ Item_sum_sum::Item_sum_sum(THD *thd, Item_sum_sum *item) :Item_sum_num(thd, item), Type_handler_hybrid_field_type(item), curr_dec_buff(item->curr_dec_buff), count(item->count) { /* TODO: check if the following assignments are really needed */ if (Item_sum_sum::result_type() == DECIMAL_RESULT) { my_decimal2decimal(item->dec_buffs, dec_buffs); my_decimal2decimal(item->dec_buffs + 1, dec_buffs + 1); } else sum= item->sum; } Item *Item_sum_sum::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_sum(thd, this); } void Item_sum_sum::clear() { DBUG_ENTER("Item_sum_sum::clear"); null_value=1; count= 0; if (Item_sum_sum::result_type() == DECIMAL_RESULT) { curr_dec_buff= 0; my_decimal_set_zero(dec_buffs); } else sum= 0.0; DBUG_VOID_RETURN; } void Item_sum_sum::fix_length_and_dec() { DBUG_ENTER("Item_sum_sum::fix_length_and_dec"); maybe_null=null_value=1; decimals= args[0]->decimals; switch (args[0]->cast_to_int_type()) { case REAL_RESULT: case STRING_RESULT: set_handler_by_field_type(MYSQL_TYPE_DOUBLE); sum= 0.0; break; case INT_RESULT: case TIME_RESULT: case DECIMAL_RESULT: { /* SUM result can't be longer than length(arg) + length(MAX_ROWS) */ int precision= args[0]->decimal_precision() + DECIMAL_LONGLONG_DIGITS; max_length= my_decimal_precision_to_length_no_truncation(precision, decimals, unsigned_flag); curr_dec_buff= 0; set_handler_by_field_type(MYSQL_TYPE_NEWDECIMAL); my_decimal_set_zero(dec_buffs); break; } case ROW_RESULT: DBUG_ASSERT(0); } DBUG_PRINT("info", ("Type: %s (%d, %d)", (result_type() == REAL_RESULT ? "REAL_RESULT" : result_type() == DECIMAL_RESULT ? "DECIMAL_RESULT" : result_type() == INT_RESULT ? "INT_RESULT" : "--ILLEGAL!!!--"), max_length, (int)decimals)); DBUG_VOID_RETURN; } bool Item_sum_sum::add() { DBUG_ENTER("Item_sum_sum::add"); add_helper(false); DBUG_RETURN(0); } void Item_sum_sum::add_helper(bool perform_removal) { DBUG_ENTER("Item_sum_sum::add_helper"); if (Item_sum_sum::result_type() == DECIMAL_RESULT) { my_decimal value; const my_decimal *val= aggr->arg_val_decimal(&value); if (!aggr->arg_is_null(true)) { if (perform_removal) { if (count > 0) { my_decimal_sub(E_DEC_FATAL_ERROR, dec_buffs + (curr_dec_buff ^ 1), dec_buffs + curr_dec_buff, val); count--; } else DBUG_VOID_RETURN; } else { count++; my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs + (curr_dec_buff ^ 1), val, dec_buffs + curr_dec_buff); } curr_dec_buff^= 1; null_value= (count > 0) ? 0 : 1; } } else { if (perform_removal && count > 0) sum-= aggr->arg_val_real(); else sum+= aggr->arg_val_real(); if (!aggr->arg_is_null(true)) { if (perform_removal) { if (count > 0) { count--; } } else count++; null_value= (count > 0) ? 0 : 1; } } DBUG_VOID_RETURN; } longlong Item_sum_sum::val_int() { DBUG_ASSERT(fixed == 1); if (aggr) aggr->endup(); if (Item_sum_sum::result_type() == DECIMAL_RESULT) { longlong result; my_decimal2int(E_DEC_FATAL_ERROR, dec_buffs + curr_dec_buff, unsigned_flag, &result); return result; } return val_int_from_real(); } double Item_sum_sum::val_real() { DBUG_ASSERT(fixed == 1); if (aggr) aggr->endup(); if (Item_sum_sum::result_type() == DECIMAL_RESULT) my_decimal2double(E_DEC_FATAL_ERROR, dec_buffs + curr_dec_buff, &sum); return sum; } String *Item_sum_sum::val_str(String *str) { if (aggr) aggr->endup(); if (Item_sum_sum::result_type() == DECIMAL_RESULT) return val_string_from_decimal(str); return val_string_from_real(str); } my_decimal *Item_sum_sum::val_decimal(my_decimal *val) { if (aggr) aggr->endup(); if (Item_sum_sum::result_type() == DECIMAL_RESULT) return null_value ? NULL : (dec_buffs + curr_dec_buff); return val_decimal_from_real(val); } void Item_sum_sum::remove() { DBUG_ENTER("Item_sum_sum::remove"); add_helper(true); DBUG_VOID_RETURN; } /** Aggregate a distinct row from the distinct hash table. Called for each row into the hash table 'Aggregator_distinct::table'. Includes the current distinct row into the calculation of the aggregate value. Uses the Field classes to get the value from the row. This function is used for AVG/SUM(DISTINCT). For COUNT(DISTINCT) it's called only when there are no blob arguments and the data don't fit into memory (so Unique makes persisted trees on disk). @param element pointer to the row data. @return status @retval FALSE success @retval TRUE failure */ bool Aggregator_distinct::unique_walk_function(void *element) { memcpy(table->field[0]->ptr, element, tree_key_length); item_sum->add(); return 0; } /* A variant of unique_walk_function() that is to be used with Item_sum_count. COUNT is a special aggregate function: it doesn't need the values, it only needs to count them. COUNT needs to know the values are not NULLs, but NULL values are not put into the Unique, so we don't need to check for NULLs here. */ bool Aggregator_distinct::unique_walk_function_for_count(void *element) { Item_sum_count *sum= (Item_sum_count *)item_sum; sum->count++; return 0; } Aggregator_distinct::~Aggregator_distinct() { if (tree) { delete tree; tree= NULL; } if (table) { free_tmp_table(table->in_use, table); table=NULL; } if (tmp_table_param) { delete tmp_table_param; tmp_table_param= NULL; } } my_decimal *Aggregator_simple::arg_val_decimal(my_decimal *value) { return item_sum->args[0]->val_decimal(value); } double Aggregator_simple::arg_val_real() { return item_sum->args[0]->val_real(); } bool Aggregator_simple::arg_is_null(bool use_null_value) { Item **item= item_sum->args; const uint item_count= item_sum->arg_count; if (use_null_value) { for (uint i= 0; i < item_count; i++) { if (item[i]->null_value) return true; } } else { for (uint i= 0; i < item_count; i++) { if (item[i]->maybe_null && item[i]->is_null()) return true; } } return false; } my_decimal *Aggregator_distinct::arg_val_decimal(my_decimal * value) { return use_distinct_values ? table->field[0]->val_decimal(value) : item_sum->args[0]->val_decimal(value); } double Aggregator_distinct::arg_val_real() { return use_distinct_values ? table->field[0]->val_real() : item_sum->args[0]->val_real(); } bool Aggregator_distinct::arg_is_null(bool use_null_value) { if (use_distinct_values) { const bool rc= table->field[0]->is_null(); DBUG_ASSERT(!rc); // NULLs are never stored in 'tree' return rc; } return use_null_value ? item_sum->args[0]->null_value : (item_sum->args[0]->maybe_null && item_sum->args[0]->is_null()); } Item *Item_sum_count::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_count(thd, this); } void Item_sum_count::clear() { count= 0; } bool Item_sum_count::add() { if (aggr->arg_is_null(false)) return 0; count++; return 0; } /* Remove a row. This is used by window functions. */ void Item_sum_count::remove() { DBUG_ASSERT(aggr->Aggrtype() == Aggregator::SIMPLE_AGGREGATOR); if (aggr->arg_is_null(false)) return; if (count > 0) count--; } longlong Item_sum_count::val_int() { DBUG_ASSERT(fixed == 1); if (aggr) aggr->endup(); return (longlong) count; } void Item_sum_count::cleanup() { DBUG_ENTER("Item_sum_count::cleanup"); count= 0; Item_sum_int::cleanup(); DBUG_VOID_RETURN; } /* Avgerage */ void Item_sum_avg::fix_length_and_dec() { Item_sum_sum::fix_length_and_dec(); maybe_null=null_value=1; prec_increment= current_thd->variables.div_precincrement; if (Item_sum_avg::result_type() == DECIMAL_RESULT) { int precision= args[0]->decimal_precision() + prec_increment; decimals= MY_MIN(args[0]->decimals + prec_increment, DECIMAL_MAX_SCALE); max_length= my_decimal_precision_to_length_no_truncation(precision, decimals, unsigned_flag); f_precision= MY_MIN(precision+DECIMAL_LONGLONG_DIGITS, DECIMAL_MAX_PRECISION); f_scale= args[0]->decimals; dec_bin_size= my_decimal_get_binary_size(f_precision, f_scale); } else { decimals= MY_MIN(args[0]->decimals + prec_increment, FLOATING_POINT_DECIMALS); max_length= MY_MIN(args[0]->max_length + prec_increment, float_length(decimals)); } } Item *Item_sum_avg::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_avg(thd, this); } Field *Item_sum_avg::create_tmp_field(bool group, TABLE *table) { Field *field; MEM_ROOT *mem_root= table->in_use->mem_root; if (group) { /* We must store both value and counter in the temporary table in one field. The easiest way is to do this is to store both value in a string and unpack on access. */ field= new (mem_root) Field_string(((Item_sum_avg::result_type() == DECIMAL_RESULT) ? dec_bin_size : sizeof(double)) + sizeof(longlong), 0, name, &my_charset_bin); } else if (Item_sum_avg::result_type() == DECIMAL_RESULT) field= Field_new_decimal::create_from_item(mem_root, this); else field= new (mem_root) Field_double(max_length, maybe_null, name, decimals, TRUE); if (field) field->init(table); return field; } void Item_sum_avg::clear() { Item_sum_sum::clear(); count=0; } bool Item_sum_avg::add() { if (Item_sum_sum::add()) return TRUE; if (!aggr->arg_is_null(true)) count++; return FALSE; } void Item_sum_avg::remove() { Item_sum_sum::remove(); if (!aggr->arg_is_null(true)) { if (count > 0) count--; } } double Item_sum_avg::val_real() { DBUG_ASSERT(fixed == 1); if (aggr) aggr->endup(); if (!count) { null_value=1; return 0.0; } return Item_sum_sum::val_real() / ulonglong2double(count); } my_decimal *Item_sum_avg::val_decimal(my_decimal *val) { my_decimal cnt; const my_decimal *sum_dec; DBUG_ASSERT(fixed == 1); if (aggr) aggr->endup(); if (!count) { null_value=1; return NULL; } /* For non-DECIMAL result_type() the division will be done in Item_sum_avg::val_real(). */ if (Item_sum_avg::result_type() != DECIMAL_RESULT) return val_decimal_from_real(val); sum_dec= dec_buffs + curr_dec_buff; int2my_decimal(E_DEC_FATAL_ERROR, count, 0, &cnt); my_decimal_div(E_DEC_FATAL_ERROR, val, sum_dec, &cnt, prec_increment); return val; } String *Item_sum_avg::val_str(String *str) { if (aggr) aggr->endup(); if (Item_sum_avg::result_type() == DECIMAL_RESULT) return val_string_from_decimal(str); return val_string_from_real(str); } /* Standard deviation */ double Item_sum_std::val_real() { DBUG_ASSERT(fixed == 1); double nr= Item_sum_variance::val_real(); if (my_isinf(nr)) return DBL_MAX; DBUG_ASSERT(nr >= 0.0); return sqrt(nr); } Item *Item_sum_std::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_std(thd, this); } Item *Item_sum_std::result_item(THD *thd, Field *field) { return new (thd->mem_root) Item_std_field(thd, this); } /* Variance */ /** Variance implementation for floating-point implementations, without catastrophic cancellation, from Knuth's _TAoCP_, 3rd ed, volume 2, pg232. This alters the value at m, s, and increments count. */ /* These two functions are used by the Item_sum_variance and the Item_variance_field classes, which are unrelated, and each need to calculate variance. The difference between the two classes is that the first is used for a mundane SELECT, while the latter is used in a GROUPing SELECT. */ static void variance_fp_recurrence_next(double *m, double *s, ulonglong *count, double nr) { *count += 1; if (*count == 1) { *m= nr; *s= 0; } else { double m_kminusone= *m; *m= m_kminusone + (nr - m_kminusone) / (double) *count; *s= *s + (nr - m_kminusone) * (nr - *m); } } static double variance_fp_recurrence_result(double s, ulonglong count, bool is_sample_variance) { if (count == 1) return 0.0; if (is_sample_variance) return s / (count - 1); /* else, is a population variance */ return s / count; } Item_sum_variance::Item_sum_variance(THD *thd, Item_sum_variance *item): Item_sum_num(thd, item), count(item->count), sample(item->sample), prec_increment(item->prec_increment) { recurrence_m= item->recurrence_m; recurrence_s= item->recurrence_s; } void Item_sum_variance::fix_length_and_dec() { DBUG_ENTER("Item_sum_variance::fix_length_and_dec"); maybe_null= null_value= 1; prec_increment= current_thd->variables.div_precincrement; /* According to the SQL2003 standard (Part 2, Foundations; sec 10.9, aggregate function; paragraph 7h of Syntax Rules), "the declared type of the result is an implementation-defined aproximate numeric type. */ switch (args[0]->result_type()) { case REAL_RESULT: case STRING_RESULT: decimals= MY_MIN(args[0]->decimals + 4, FLOATING_POINT_DECIMALS); break; case INT_RESULT: case DECIMAL_RESULT: { int precision= args[0]->decimal_precision()*2 + prec_increment; decimals= MY_MIN(args[0]->decimals + prec_increment, FLOATING_POINT_DECIMALS-1); max_length= my_decimal_precision_to_length_no_truncation(precision, decimals, unsigned_flag); break; } case ROW_RESULT: case TIME_RESULT: DBUG_ASSERT(0); } DBUG_PRINT("info", ("Type: REAL_RESULT (%d, %d)", max_length, (int)decimals)); DBUG_VOID_RETURN; } Item *Item_sum_variance::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_variance(thd, this); } /** Create a new field to match the type of value we're expected to yield. If we're grouping, then we need some space to serialize variables into, to pass around. */ Field *Item_sum_variance::create_tmp_field(bool group, TABLE *table) { Field *field; if (group) { /* We must store both value and counter in the temporary table in one field. The easiest way is to do this is to store both value in a string and unpack on access. */ field= new Field_string(sizeof(double)*2 + sizeof(longlong), 0, name, &my_charset_bin); } else field= new Field_double(max_length, maybe_null, name, decimals, TRUE); if (field != NULL) field->init(table); return field; } void Item_sum_variance::clear() { count= 0; } bool Item_sum_variance::add() { /* Why use a temporary variable? We don't know if it is null until we evaluate it, which has the side-effect of setting null_value . */ double nr= args[0]->val_real(); if (!args[0]->null_value) variance_fp_recurrence_next(&recurrence_m, &recurrence_s, &count, nr); return 0; } double Item_sum_variance::val_real() { DBUG_ASSERT(fixed == 1); /* 'sample' is a 1/0 boolean value. If it is 1/true, id est this is a sample variance call, then we should set nullness when the count of the items is one or zero. If it's zero, i.e. a population variance, then we only set nullness when the count is zero. Another way to read it is that 'sample' is the numerical threshhold, at and below which a 'count' number of items is called NULL. */ DBUG_ASSERT((sample == 0) || (sample == 1)); if (count <= sample) { null_value=1; return 0.0; } null_value=0; return variance_fp_recurrence_result(recurrence_s, count, sample); } my_decimal *Item_sum_variance::val_decimal(my_decimal *dec_buf) { DBUG_ASSERT(fixed == 1); return val_decimal_from_real(dec_buf); } void Item_sum_variance::reset_field() { double nr; uchar *res= result_field->ptr; nr= args[0]->val_real(); /* sets null_value as side-effect */ if (args[0]->null_value) bzero(res,sizeof(double)*2+sizeof(longlong)); else { /* Serialize format is (double)m, (double)s, (longlong)count */ ulonglong tmp_count; double tmp_s; float8store(res, nr); /* recurrence variable m */ tmp_s= 0.0; float8store(res + sizeof(double), tmp_s); tmp_count= 1; int8store(res + sizeof(double)*2, tmp_count); } } void Item_sum_variance::update_field() { ulonglong field_count; uchar *res=result_field->ptr; double nr= args[0]->val_real(); /* sets null_value as side-effect */ if (args[0]->null_value) return; /* Serialize format is (double)m, (double)s, (longlong)count */ double field_recurrence_m, field_recurrence_s; float8get(field_recurrence_m, res); float8get(field_recurrence_s, res + sizeof(double)); field_count=sint8korr(res+sizeof(double)*2); variance_fp_recurrence_next(&field_recurrence_m, &field_recurrence_s, &field_count, nr); float8store(res, field_recurrence_m); float8store(res + sizeof(double), field_recurrence_s); res+= sizeof(double)*2; int8store(res,field_count); } Item *Item_sum_variance::result_item(THD *thd, Field *field) { return new (thd->mem_root) Item_variance_field(thd, this); } /* min & max */ void Item_sum_hybrid::clear() { value->clear(); null_value= 1; } double Item_sum_hybrid::val_real() { DBUG_ASSERT(fixed == 1); if (null_value) return 0.0; double retval= value->val_real(); if ((null_value= value->null_value)) DBUG_ASSERT(retval == 0.0); return retval; } longlong Item_sum_hybrid::val_int() { DBUG_ASSERT(fixed == 1); if (null_value) return 0; longlong retval= value->val_int(); if ((null_value= value->null_value)) DBUG_ASSERT(retval == 0); return retval; } my_decimal *Item_sum_hybrid::val_decimal(my_decimal *val) { DBUG_ASSERT(fixed == 1); if (null_value) return 0; my_decimal *retval= value->val_decimal(val); if ((null_value= value->null_value)) DBUG_ASSERT(retval == NULL); return retval; } String * Item_sum_hybrid::val_str(String *str) { DBUG_ASSERT(fixed == 1); if (null_value) return 0; String *retval= value->val_str(str); if ((null_value= value->null_value)) DBUG_ASSERT(retval == NULL); return retval; } void Item_sum_hybrid::cleanup() { DBUG_ENTER("Item_sum_hybrid::cleanup"); Item_sum::cleanup(); if (cmp) delete cmp; cmp= 0; /* by default it is TRUE to avoid TRUE reporting by Item_func_not_all/Item_func_nop_all if this item was never called. no_rows_in_result() set it to FALSE if was not results found. If some results found it will be left unchanged. */ was_values= TRUE; DBUG_VOID_RETURN; } void Item_sum_hybrid::no_rows_in_result() { /* We may be called here twice in case of ref field in function */ if (was_values) { was_values= FALSE; was_null_value= value->null_value; clear(); } } void Item_sum_hybrid::restore_to_before_no_rows_in_result() { if (!was_values) { was_values= TRUE; null_value= value->null_value= was_null_value; } } Item *Item_sum_min::copy_or_same(THD* thd) { Item_sum_min *item= new (thd->mem_root) Item_sum_min(thd, this); item->setup_hybrid(thd, args[0], value); return item; } bool Item_sum_min::add() { /* args[0] < value */ arg_cache->cache_value(); if (!arg_cache->null_value && (null_value || cmp->compare() < 0)) { value->store(arg_cache); value->cache_value(); null_value= 0; } return 0; } Item *Item_sum_max::copy_or_same(THD* thd) { Item_sum_max *item= new (thd->mem_root) Item_sum_max(thd, this); item->setup_hybrid(thd, args[0], value); return item; } bool Item_sum_max::add() { /* args[0] > value */ arg_cache->cache_value(); if (!arg_cache->null_value && (null_value || cmp->compare() > 0)) { value->store(arg_cache); value->cache_value(); null_value= 0; } return 0; } /* bit_or and bit_and */ longlong Item_sum_bit::val_int() { DBUG_ASSERT(fixed == 1); return (longlong) bits; } void Item_sum_bit::clear() { bits= reset_bits; if (as_window_function) clear_as_window(); } Item *Item_sum_or::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_or(thd, this); } bool Item_sum_bit::clear_as_window() { memset(bit_counters, 0, sizeof(bit_counters)); num_values_added= 0; set_bits_from_counters(); return 0; } bool Item_sum_bit::remove_as_window(ulonglong value) { DBUG_ASSERT(as_window_function); if (num_values_added == 0) return 0; // Nothing to remove. for (int i= 0; i < NUM_BIT_COUNTERS; i++) { if (!bit_counters[i]) { // Don't attempt to remove values that were never added. DBUG_ASSERT((value & (1 << i)) == 0); continue; } bit_counters[i]-= (value & (1 << i)) ? 1 : 0; } // Prevent overflow; num_values_added = std::min(num_values_added, num_values_added - 1); set_bits_from_counters(); return 0; } bool Item_sum_bit::add_as_window(ulonglong value) { DBUG_ASSERT(as_window_function); for (int i= 0; i < NUM_BIT_COUNTERS; i++) { bit_counters[i]+= (value & (1 << i)) ? 1 : 0; } // Prevent overflow; num_values_added = std::max(num_values_added, num_values_added + 1); set_bits_from_counters(); return 0; } void Item_sum_or::set_bits_from_counters() { ulonglong value= 0; for (int i= 0; i < NUM_BIT_COUNTERS; i++) { value|= bit_counters[i] > 0 ? (1 << i) : 0; } bits= value | reset_bits; } bool Item_sum_or::add() { ulonglong value= (ulonglong) args[0]->val_int(); if (!args[0]->null_value) { if (as_window_function) return add_as_window(value); bits|=value; } return 0; } void Item_sum_xor::set_bits_from_counters() { ulonglong value= 0; for (int i= 0; i < NUM_BIT_COUNTERS; i++) { value|= (bit_counters[i] % 2) ? (1 << i) : 0; } bits= value ^ reset_bits; } Item *Item_sum_xor::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_xor(thd, this); } bool Item_sum_xor::add() { ulonglong value= (ulonglong) args[0]->val_int(); if (!args[0]->null_value) { if (as_window_function) return add_as_window(value); bits^=value; } return 0; } void Item_sum_and::set_bits_from_counters() { ulonglong value= 0; if (!num_values_added) { bits= reset_bits; return; } for (int i= 0; i < NUM_BIT_COUNTERS; i++) { // We've only added values of 1 for this bit. if (bit_counters[i] == num_values_added) value|= (1 << i); } bits= value & reset_bits; } Item *Item_sum_and::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_and(thd, this); } bool Item_sum_and::add() { ulonglong value= (ulonglong) args[0]->val_int(); if (!args[0]->null_value) { if (as_window_function) return add_as_window(value); bits&=value; } return 0; } /************************************************************************ ** reset result of a Item_sum with is saved in a tmp_table *************************************************************************/ void Item_sum_num::reset_field() { double nr= args[0]->val_real(); uchar *res=result_field->ptr; if (maybe_null) { if (args[0]->null_value) { nr=0.0; result_field->set_null(); } else result_field->set_notnull(); } float8store(res,nr); } void Item_sum_hybrid::reset_field() { switch(Item_sum_hybrid::result_type()) { case STRING_RESULT: { char buff[MAX_FIELD_WIDTH]; String tmp(buff,sizeof(buff),result_field->charset()),*res; res=args[0]->val_str(&tmp); if (args[0]->null_value) { result_field->set_null(); result_field->reset(); } else { result_field->set_notnull(); result_field->store(res->ptr(),res->length(),tmp.charset()); } break; } case INT_RESULT: { longlong nr=args[0]->val_int(); if (maybe_null) { if (args[0]->null_value) { nr=0; result_field->set_null(); } else result_field->set_notnull(); } result_field->store(nr, unsigned_flag); break; } case REAL_RESULT: { double nr= args[0]->val_real(); if (maybe_null) { if (args[0]->null_value) { nr=0.0; result_field->set_null(); } else result_field->set_notnull(); } result_field->store(nr); break; } case DECIMAL_RESULT: { my_decimal value_buff, *arg_dec= args[0]->val_decimal(&value_buff); if (maybe_null) { if (args[0]->null_value) result_field->set_null(); else result_field->set_notnull(); } /* We must store zero in the field as we will use the field value in add() */ if (!arg_dec) // Null arg_dec= &decimal_zero; result_field->store_decimal(arg_dec); break; } case ROW_RESULT: case TIME_RESULT: DBUG_ASSERT(0); } } void Item_sum_sum::reset_field() { DBUG_ASSERT (aggr->Aggrtype() != Aggregator::DISTINCT_AGGREGATOR); if (Item_sum_sum::result_type() == DECIMAL_RESULT) { my_decimal value, *arg_val= args[0]->val_decimal(&value); if (!arg_val) // Null arg_val= &decimal_zero; result_field->store_decimal(arg_val); } else { DBUG_ASSERT(result_type() == REAL_RESULT); double nr= args[0]->val_real(); // Nulls also return 0 float8store(result_field->ptr, nr); } if (args[0]->null_value) result_field->set_null(); else result_field->set_notnull(); } void Item_sum_count::reset_field() { uchar *res=result_field->ptr; longlong nr=0; DBUG_ASSERT (aggr->Aggrtype() != Aggregator::DISTINCT_AGGREGATOR); if (!args[0]->maybe_null || !args[0]->is_null()) nr=1; int8store(res,nr); } void Item_sum_avg::reset_field() { uchar *res=result_field->ptr; DBUG_ASSERT (aggr->Aggrtype() != Aggregator::DISTINCT_AGGREGATOR); if (Item_sum_avg::result_type() == DECIMAL_RESULT) { longlong tmp; my_decimal value, *arg_dec= args[0]->val_decimal(&value); if (args[0]->null_value) { arg_dec= &decimal_zero; tmp= 0; } else tmp= 1; my_decimal2binary(E_DEC_FATAL_ERROR, arg_dec, res, f_precision, f_scale); res+= dec_bin_size; int8store(res, tmp); } else { double nr= args[0]->val_real(); if (args[0]->null_value) bzero(res,sizeof(double)+sizeof(longlong)); else { longlong tmp= 1; float8store(res,nr); res+=sizeof(double); int8store(res,tmp); } } } void Item_sum_bit::reset_field() { reset_and_add(); int8store(result_field->ptr, bits); } void Item_sum_bit::update_field() { // We never call update_field when computing the function as a window // function. Setting bits to a random value invalidates the bits counters and // the result of the bit function becomes erroneous. DBUG_ASSERT(!as_window_function); uchar *res=result_field->ptr; bits= uint8korr(res); add(); int8store(res, bits); } /** calc next value and merge it with field_value. */ void Item_sum_sum::update_field() { DBUG_ASSERT (aggr->Aggrtype() != Aggregator::DISTINCT_AGGREGATOR); if (Item_sum_sum::result_type() == DECIMAL_RESULT) { my_decimal value, *arg_val= args[0]->val_decimal(&value); if (!args[0]->null_value) { if (!result_field->is_null()) { my_decimal field_value, *field_val= result_field->val_decimal(&field_value); my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs, arg_val, field_val); result_field->store_decimal(dec_buffs); } else { result_field->store_decimal(arg_val); result_field->set_notnull(); } } } else { double old_nr,nr; uchar *res=result_field->ptr; float8get(old_nr,res); nr= args[0]->val_real(); if (!args[0]->null_value) { old_nr+=nr; result_field->set_notnull(); } float8store(res,old_nr); } } void Item_sum_count::update_field() { longlong nr; uchar *res=result_field->ptr; nr=sint8korr(res); if (!args[0]->maybe_null || !args[0]->is_null()) nr++; int8store(res,nr); } void Item_sum_avg::update_field() { longlong field_count; uchar *res=result_field->ptr; DBUG_ASSERT (aggr->Aggrtype() != Aggregator::DISTINCT_AGGREGATOR); if (Item_sum_avg::result_type() == DECIMAL_RESULT) { my_decimal value, *arg_val= args[0]->val_decimal(&value); if (!args[0]->null_value) { binary2my_decimal(E_DEC_FATAL_ERROR, res, dec_buffs + 1, f_precision, f_scale); field_count= sint8korr(res + dec_bin_size); my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs, arg_val, dec_buffs + 1); my_decimal2binary(E_DEC_FATAL_ERROR, dec_buffs, res, f_precision, f_scale); res+= dec_bin_size; field_count++; int8store(res, field_count); } } else { double nr; nr= args[0]->val_real(); if (!args[0]->null_value) { double old_nr; float8get(old_nr, res); field_count= sint8korr(res + sizeof(double)); old_nr+= nr; float8store(res,old_nr); res+= sizeof(double); field_count++; int8store(res, field_count); } } } Item *Item_sum_avg::result_item(THD *thd, Field *field) { return Item_sum_avg::result_type() == DECIMAL_RESULT ? (Item_avg_field*) new (thd->mem_root) Item_avg_field_decimal(thd, this) : (Item_avg_field*) new (thd->mem_root) Item_avg_field_double(thd, this); } void Item_sum_hybrid::update_field() { switch (Item_sum_hybrid::result_type()) { case STRING_RESULT: min_max_update_str_field(); break; case INT_RESULT: min_max_update_int_field(); break; case DECIMAL_RESULT: min_max_update_decimal_field(); break; default: min_max_update_real_field(); } } void Item_sum_hybrid::min_max_update_str_field() { DBUG_ASSERT(cmp); String *res_str=args[0]->val_str(&cmp->value1); if (!args[0]->null_value) { result_field->val_str(&cmp->value2); if (result_field->is_null() || (cmp_sign * sortcmp(res_str,&cmp->value2,collation.collation)) < 0) result_field->store(res_str->ptr(),res_str->length(),res_str->charset()); result_field->set_notnull(); } } void Item_sum_hybrid::min_max_update_real_field() { double nr,old_nr; old_nr=result_field->val_real(); nr= args[0]->val_real(); if (!args[0]->null_value) { if (result_field->is_null(0) || (cmp_sign > 0 ? old_nr > nr : old_nr < nr)) old_nr=nr; result_field->set_notnull(); } else if (result_field->is_null(0)) result_field->set_null(); result_field->store(old_nr); } void Item_sum_hybrid::min_max_update_int_field() { longlong nr,old_nr; old_nr=result_field->val_int(); nr=args[0]->val_int(); if (!args[0]->null_value) { if (result_field->is_null(0)) old_nr=nr; else { bool res=(unsigned_flag ? (ulonglong) old_nr > (ulonglong) nr : old_nr > nr); /* (cmp_sign > 0 && res) || (!(cmp_sign > 0) && !res) */ if ((cmp_sign > 0) ^ (!res)) old_nr=nr; } result_field->set_notnull(); } else if (result_field->is_null(0)) result_field->set_null(); result_field->store(old_nr, unsigned_flag); } /** @todo optimize: do not get result_field in case of args[0] is NULL */ void Item_sum_hybrid::min_max_update_decimal_field() { my_decimal old_val, nr_val; const my_decimal *old_nr; const my_decimal *nr= args[0]->val_decimal(&nr_val); if (!args[0]->null_value) { if (result_field->is_null(0)) old_nr=nr; else { old_nr= result_field->val_decimal(&old_val); bool res= my_decimal_cmp(old_nr, nr) > 0; /* (cmp_sign > 0 && res) || (!(cmp_sign > 0) && !res) */ if ((cmp_sign > 0) ^ (!res)) old_nr=nr; } result_field->set_notnull(); result_field->store_decimal(old_nr); } else if (result_field->is_null(0)) result_field->set_null(); } double Item_avg_field_double::val_real() { // fix_fields() never calls for this Item double nr; longlong count; uchar *res; float8get(nr,field->ptr); res= (field->ptr+sizeof(double)); count= sint8korr(res); if ((null_value= !count)) return 0.0; return nr/(double) count; } my_decimal *Item_avg_field_decimal::val_decimal(my_decimal *dec_buf) { // fix_fields() never calls for this Item longlong count= sint8korr(field->ptr + dec_bin_size); if ((null_value= !count)) return 0; my_decimal dec_count, dec_field; binary2my_decimal(E_DEC_FATAL_ERROR, field->ptr, &dec_field, f_precision, f_scale); int2my_decimal(E_DEC_FATAL_ERROR, count, 0, &dec_count); my_decimal_div(E_DEC_FATAL_ERROR, dec_buf, &dec_field, &dec_count, prec_increment); return dec_buf; } double Item_std_field::val_real() { double nr; // fix_fields() never calls for this Item nr= Item_variance_field::val_real(); DBUG_ASSERT(nr >= 0.0); return sqrt(nr); } double Item_variance_field::val_real() { // fix_fields() never calls for this Item double recurrence_s; ulonglong count; float8get(recurrence_s, (field->ptr + sizeof(double))); count=sint8korr(field->ptr+sizeof(double)*2); if ((null_value= (count <= sample))) return 0.0; return variance_fp_recurrence_result(recurrence_s, count, sample); } /**************************************************************************** ** Functions to handle dynamic loadable aggregates ** Original source by: Alexis Mikhailov ** Adapted for UDAs by: Andreas F. Bobak . ** Rewritten by: Monty. ****************************************************************************/ #ifdef HAVE_DLOPEN void Item_udf_sum::clear() { DBUG_ENTER("Item_udf_sum::clear"); udf.clear(); DBUG_VOID_RETURN; } bool Item_udf_sum::add() { my_bool tmp_null_value; DBUG_ENTER("Item_udf_sum::add"); udf.add(&tmp_null_value); null_value= tmp_null_value; DBUG_RETURN(0); } void Item_udf_sum::cleanup() { /* udf_handler::cleanup() nicely handles case when we have not original item but one created by copy_or_same() method. */ udf.cleanup(); Item_sum::cleanup(); } void Item_udf_sum::print(String *str, enum_query_type query_type) { str->append(func_name()); str->append('('); for (uint i=0 ; i < arg_count ; i++) { if (i) str->append(','); args[i]->print(str, query_type); } str->append(')'); } Item *Item_sum_udf_float::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_udf_float(thd, this); } double Item_sum_udf_float::val_real() { my_bool tmp_null_value; double res; DBUG_ASSERT(fixed == 1); DBUG_ENTER("Item_sum_udf_float::val"); DBUG_PRINT("info",("result_type: %d arg_count: %d", args[0]->result_type(), arg_count)); res= udf.val(&tmp_null_value); null_value= tmp_null_value; DBUG_RETURN(res); } String *Item_sum_udf_float::val_str(String *str) { return val_string_from_real(str); } my_decimal *Item_sum_udf_float::val_decimal(my_decimal *dec) { return val_decimal_from_real(dec); } String *Item_sum_udf_decimal::val_str(String *str) { return val_string_from_decimal(str); } double Item_sum_udf_decimal::val_real() { return val_real_from_decimal(); } longlong Item_sum_udf_decimal::val_int() { return val_int_from_decimal(); } my_decimal *Item_sum_udf_decimal::val_decimal(my_decimal *dec_buf) { my_decimal *res; my_bool tmp_null_value; DBUG_ASSERT(fixed == 1); DBUG_ENTER("Item_func_udf_decimal::val_decimal"); DBUG_PRINT("info",("result_type: %d arg_count: %d", args[0]->result_type(), arg_count)); res= udf.val_decimal(&tmp_null_value, dec_buf); null_value= tmp_null_value; DBUG_RETURN(res); } Item *Item_sum_udf_decimal::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_udf_decimal(thd, this); } Item *Item_sum_udf_int::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_udf_int(thd, this); } longlong Item_sum_udf_int::val_int() { my_bool tmp_null_value; longlong res; DBUG_ASSERT(fixed == 1); DBUG_ENTER("Item_sum_udf_int::val_int"); DBUG_PRINT("info",("result_type: %d arg_count: %d", args[0]->result_type(), arg_count)); res= udf.val_int(&tmp_null_value); null_value= tmp_null_value; DBUG_RETURN(res); } String *Item_sum_udf_int::val_str(String *str) { return val_string_from_int(str); } my_decimal *Item_sum_udf_int::val_decimal(my_decimal *dec) { return val_decimal_from_int(dec); } /** Default max_length is max argument length. */ void Item_sum_udf_str::fix_length_and_dec() { DBUG_ENTER("Item_sum_udf_str::fix_length_and_dec"); max_length=0; for (uint i = 0; i < arg_count; i++) set_if_bigger(max_length,args[i]->max_length); DBUG_VOID_RETURN; } Item *Item_sum_udf_str::copy_or_same(THD* thd) { return new (thd->mem_root) Item_sum_udf_str(thd, this); } my_decimal *Item_sum_udf_str::val_decimal(my_decimal *dec) { return val_decimal_from_string(dec); } String *Item_sum_udf_str::val_str(String *str) { DBUG_ASSERT(fixed == 1); DBUG_ENTER("Item_sum_udf_str::str"); String *res=udf.val_str(str,&str_value); null_value = !res; DBUG_RETURN(res); } #endif /* HAVE_DLOPEN */ /***************************************************************************** GROUP_CONCAT function SQL SYNTAX: GROUP_CONCAT([DISTINCT] expr,... [ORDER BY col [ASC|DESC],...] [SEPARATOR str_const]) concat of values from "group by" operation BUGS Blobs doesn't work with DISTINCT or ORDER BY *****************************************************************************/ /** Compares the values for fields in expr list of GROUP_CONCAT. @note GROUP_CONCAT([DISTINCT] expr [,expr ...] [ORDER BY {unsigned_integer | col_name | expr} [ASC | DESC] [,col_name ...]] [SEPARATOR str_val]) @return @retval -1 : key1 < key2 @retval 0 : key1 = key2 @retval 1 : key1 > key2 */ extern "C" int group_concat_key_cmp_with_distinct(void* arg, const void* key1, const void* key2) { Item_func_group_concat *item_func= (Item_func_group_concat*)arg; for (uint i= 0; i < item_func->arg_count_field; i++) { Item *item= item_func->args[i]; /* If item is a const item then either get_tmp_table_field returns 0 or it is an item over a const table. */ if (item->const_item()) continue; /* We have to use get_tmp_table_field() instead of real_item()->get_tmp_table_field() because we want the field in the temporary table, not the original field */ Field *field= item->get_tmp_table_field(); if (!field) continue; uint offset= (field->offset(field->table->record[0]) - field->table->s->null_bytes); int res= field->cmp((uchar*)key1 + offset, (uchar*)key2 + offset); if (res) return res; } return 0; } /** function of sort for syntax: GROUP_CONCAT(expr,... ORDER BY col,... ) */ extern "C" int group_concat_key_cmp_with_order(void* arg, const void* key1, const void* key2) { Item_func_group_concat* grp_item= (Item_func_group_concat*) arg; ORDER **order_item, **end; for (order_item= grp_item->order, end=order_item+ grp_item->arg_count_order; order_item < end; order_item++) { Item *item= *(*order_item)->item; /* If field_item is a const item then either get_tmp_table_field returns 0 or it is an item over a const table. */ if (item->const_item()) continue; /* If item is a const item then either get_tmp_table_field returns 0 or it is an item over a const table. */ if (item->const_item()) continue; /* We have to use get_tmp_table_field() instead of real_item()->get_tmp_table_field() because we want the field in the temporary table, not the original field Note that for the case of ROLLUP, field may point to another table tham grp_item->table. This is however ok as the table definitions are the same. */ Field *field= item->get_tmp_table_field(); if (!field) continue; uint offset= (field->offset(field->table->record[0]) - field->table->s->null_bytes); int res= field->cmp((uchar*)key1 + offset, (uchar*)key2 + offset); if (res) return ((*order_item)->direction == ORDER::ORDER_ASC) ? res : -res; } /* We can't return 0 because in that case the tree class would remove this item as double value. This would cause problems for case-changes and if the returned values are not the same we do the sort on. */ return 1; } /** Append data from current leaf to item->result. */ extern "C" int dump_leaf_key(void* key_arg, element_count count __attribute__((unused)), void* item_arg) { Item_func_group_concat *item= (Item_func_group_concat *) item_arg; TABLE *table= item->table; uint max_length= table->in_use->variables.group_concat_max_len; String tmp((char *)table->record[1], table->s->reclength, default_charset_info); String tmp2; uchar *key= (uchar *) key_arg; String *result= &item->result; Item **arg= item->args, **arg_end= item->args + item->arg_count_field; uint old_length= result->length(); if (item->no_appended) item->no_appended= FALSE; else result->append(*item->separator); tmp.length(0); for (; arg < arg_end; arg++) { String *res; /* We have to use get_tmp_table_field() instead of real_item()->get_tmp_table_field() because we want the field in the temporary table, not the original field We also can't use table->field array to access the fields because it contains both order and arg list fields. */ if ((*arg)->const_item()) res= (*arg)->val_str(&tmp); else { Field *field= (*arg)->get_tmp_table_field(); if (field) { uint offset= (field->offset(field->table->record[0]) - table->s->null_bytes); DBUG_ASSERT(offset < table->s->reclength); res= field->val_str(&tmp, key + offset); } else res= (*arg)->val_str(&tmp); } if (res) result->append(*res); } item->row_count++; /* stop if length of result more than max_length */ if (result->length() > max_length) { CHARSET_INFO *cs= item->collation.collation; const char *ptr= result->ptr(); THD *thd= current_thd; /* It's ok to use item->result.length() as the fourth argument as this is never used to limit the length of the data. Cut is done with the third argument. */ uint add_length= Well_formed_prefix(cs, ptr + old_length, ptr + max_length, result->length()).length(); result->length(old_length + add_length); item->warning_for_row= TRUE; push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN, ER_CUT_VALUE_GROUP_CONCAT, ER_THD(thd, ER_CUT_VALUE_GROUP_CONCAT), item->row_count); /** To avoid duplicated warnings in Item_func_group_concat::val_str() */ if (table && table->blob_storage) table->blob_storage->set_truncated_value(false); return 1; } return 0; } /** Constructor of Item_func_group_concat. @param distinct_arg distinct @param select_list list of expression for show values @param order_list list of sort columns @param separator_arg string value of separator. */ Item_func_group_concat:: Item_func_group_concat(THD *thd, Name_resolution_context *context_arg, bool distinct_arg, List *select_list, const SQL_I_List &order_list, String *separator_arg) :Item_sum(thd), tmp_table_param(0), separator(separator_arg), tree(0), unique_filter(NULL), table(0), order(0), context(context_arg), arg_count_order(order_list.elements), arg_count_field(select_list->elements), row_count(0), distinct(distinct_arg), warning_for_row(FALSE), force_copy_fields(0), original(0) { Item *item_select; Item **arg_ptr; quick_group= FALSE; arg_count= arg_count_field + arg_count_order; /* We need to allocate: args - arg_count_field+arg_count_order (for possible order items in temporary tables) order - arg_count_order */ if (!(args= (Item**) thd->alloc(sizeof(Item*) * arg_count * 2 + sizeof(ORDER*)*arg_count_order))) return; order= (ORDER**)(args + arg_count); /* fill args items of show and sort */ List_iterator_fast li(*select_list); for (arg_ptr=args ; (item_select= li++) ; arg_ptr++) *arg_ptr= item_select; if (arg_count_order) { ORDER **order_ptr= order; for (ORDER *order_item= order_list.first; order_item != NULL; order_item= order_item->next) { (*order_ptr++)= order_item; *arg_ptr= *order_item->item; order_item->item= arg_ptr++; } } /* orig_args is only used for print() */ orig_args= (Item**) (order + arg_count_order); memcpy(orig_args, args, sizeof(Item*) * arg_count); } Item_func_group_concat::Item_func_group_concat(THD *thd, Item_func_group_concat *item) :Item_sum(thd, item), tmp_table_param(item->tmp_table_param), separator(item->separator), tree(item->tree), unique_filter(item->unique_filter), table(item->table), context(item->context), arg_count_order(item->arg_count_order), arg_count_field(item->arg_count_field), row_count(item->row_count), distinct(item->distinct), warning_for_row(item->warning_for_row), always_null(item->always_null), force_copy_fields(item->force_copy_fields), original(item) { quick_group= item->quick_group; result.set_charset(collation.collation); /* Since the ORDER structures pointed to by the elements of the 'order' array may be modified in find_order_in_list() called from Item_func_group_concat::setup(), create a copy of those structures so that such modifications done in this object would not have any effect on the object being copied. */ ORDER *tmp; if (!(tmp= (ORDER *) thd->alloc(sizeof(ORDER *) * arg_count_order + sizeof(ORDER) * arg_count_order))) return; order= (ORDER **)(tmp + arg_count_order); for (uint i= 0; i < arg_count_order; i++, tmp++) { /* Compiler generated copy constructor is used to to copy all the members of ORDER struct. It's also necessary to update ORDER::next pointer so that it points to new ORDER element. */ new (tmp) st_order(*(item->order[i])); tmp->next= (i + 1 == arg_count_order) ? NULL : (tmp + 1); order[i]= tmp; } } void Item_func_group_concat::cleanup() { DBUG_ENTER("Item_func_group_concat::cleanup"); Item_sum::cleanup(); /* Free table and tree if they belong to this item (if item have not pointer to original item from which was made copy => it own its objects ) */ if (!original) { delete tmp_table_param; tmp_table_param= 0; if (table) { THD *thd= table->in_use; if (table->blob_storage) delete table->blob_storage; free_tmp_table(thd, table); table= 0; if (tree) { delete_tree(tree); tree= 0; } if (unique_filter) { delete unique_filter; unique_filter= NULL; } } DBUG_ASSERT(tree == 0); } /* As the ORDER structures pointed to by the elements of the 'order' array may be modified in find_order_in_list() called from Item_func_group_concat::setup() to point to runtime created objects, we need to reset them back to the original arguments of the function. */ ORDER **order_ptr= order; for (uint i= 0; i < arg_count_order; i++) { (*order_ptr)->item= &args[arg_count_field + i]; order_ptr++; } DBUG_VOID_RETURN; } Field *Item_func_group_concat::make_string_field(TABLE *table_arg) { Field *field; DBUG_ASSERT(collation.collation); if (too_big_for_varchar()) field= new Field_blob(max_length, maybe_null, name, collation.collation, TRUE); else field= new Field_varstring(max_length, maybe_null, name, table_arg->s, collation.collation); if (field) field->init(table_arg); return field; } Item *Item_func_group_concat::copy_or_same(THD* thd) { return new (thd->mem_root) Item_func_group_concat(thd, this); } void Item_func_group_concat::clear() { result.length(0); result.copy(); null_value= TRUE; warning_for_row= FALSE; no_appended= TRUE; if (tree) reset_tree(tree); if (unique_filter) unique_filter->reset(); if (table && table->blob_storage) table->blob_storage->reset(); /* No need to reset the table as we never call write_row */ } bool Item_func_group_concat::add() { if (always_null) return 0; copy_fields(tmp_table_param); if (copy_funcs(tmp_table_param->items_to_copy, table->in_use)) return TRUE; for (uint i= 0; i < arg_count_field; i++) { Item *show_item= args[i]; if (show_item->const_item()) continue; Field *field= show_item->get_tmp_table_field(); if (field && field->is_null_in_record((const uchar*) table->record[0])) return 0; // Skip row if it contains null } null_value= FALSE; bool row_eligible= TRUE; if (distinct) { /* Filter out duplicate rows. */ uint count= unique_filter->elements_in_tree(); unique_filter->unique_add(table->record[0] + table->s->null_bytes); if (count == unique_filter->elements_in_tree()) row_eligible= FALSE; } TREE_ELEMENT *el= 0; // Only for safety if (row_eligible && tree) { el= tree_insert(tree, table->record[0] + table->s->null_bytes, 0, tree->custom_arg); /* check if there was enough memory to insert the row */ if (!el) return 1; } /* If the row is not a duplicate (el->count == 1) we can dump the row here in case of GROUP_CONCAT(DISTINCT...) instead of doing tree traverse later. */ if (row_eligible && !warning_for_row && (!tree || (el->count == 1 && distinct && !arg_count_order))) dump_leaf_key(table->record[0] + table->s->null_bytes, 1, this); return 0; } bool Item_func_group_concat::fix_fields(THD *thd, Item **ref) { uint i; /* for loop variable */ DBUG_ASSERT(fixed == 0); if (init_sum_func_check(thd)) return TRUE; maybe_null= 1; /* Fix fields for select list and ORDER clause */ for (i=0 ; i < arg_count ; i++) { if ((!args[i]->fixed && args[i]->fix_fields(thd, args + i)) || args[i]->check_cols(1)) return TRUE; with_subselect|= args[i]->with_subselect; } /* skip charset aggregation for order columns */ if (agg_arg_charsets_for_string_result(collation, args, arg_count - arg_count_order)) return 1; result.set_charset(collation.collation); result_field= 0; null_value= 1; max_length= thd->variables.group_concat_max_len / collation.collation->mbminlen * collation.collation->mbmaxlen; uint32 offset; if (separator->needs_conversion(separator->length(), separator->charset(), collation.collation, &offset)) { uint32 buflen= collation.collation->mbmaxlen * separator->length(); uint errors, conv_length; char *buf; String *new_separator; if (!(buf= (char*) thd->stmt_arena->alloc(buflen)) || !(new_separator= new(thd->stmt_arena->mem_root) String(buf, buflen, collation.collation))) return TRUE; conv_length= copy_and_convert(buf, buflen, collation.collation, separator->ptr(), separator->length(), separator->charset(), &errors); new_separator->length(conv_length); separator= new_separator; } if (check_sum_func(thd, ref)) return TRUE; fixed= 1; return FALSE; } bool Item_func_group_concat::setup(THD *thd) { List list; SELECT_LEX *select_lex= thd->lex->current_select; const bool order_or_distinct= MY_TEST(arg_count_order > 0 || distinct); DBUG_ENTER("Item_func_group_concat::setup"); /* Currently setup() can be called twice. Please add assertion here when this is fixed. */ if (table || tree) DBUG_RETURN(FALSE); if (!(tmp_table_param= new TMP_TABLE_PARAM)) DBUG_RETURN(TRUE); /* Push all not constant fields to the list and create a temp table */ always_null= 0; for (uint i= 0; i < arg_count_field; i++) { Item *item= args[i]; if (list.push_back(item, thd->mem_root)) DBUG_RETURN(TRUE); if (item->const_item()) { if (item->is_null()) { always_null= 1; DBUG_RETURN(FALSE); } } } List all_fields(list); /* Try to find every ORDER expression in the list of GROUP_CONCAT arguments. If an expression is not found, prepend it to "all_fields". The resulting field list is used as input to create tmp table columns. */ if (arg_count_order) { uint n_elems= arg_count_order + all_fields.elements; ref_pointer_array= static_cast(thd->alloc(sizeof(Item*) * n_elems)); if (!ref_pointer_array) DBUG_RETURN(TRUE); memcpy(ref_pointer_array, args, arg_count * sizeof(Item*)); if (setup_order(thd, Ref_ptr_array(ref_pointer_array, n_elems), context->table_list, list, all_fields, *order)) DBUG_RETURN(TRUE); } count_field_types(select_lex, tmp_table_param, all_fields, 0); tmp_table_param->force_copy_fields= force_copy_fields; DBUG_ASSERT(table == 0); if (order_or_distinct) { /* Force the create_tmp_table() to convert BIT columns to INT as we cannot compare two table records containg BIT fields stored in the the tree used for distinct/order by. Moreover we don't even save in the tree record null bits where BIT fields store parts of their data. */ List_iterator_fast li(all_fields); Item *item; while ((item= li++)) { if (item->type() == Item::FIELD_ITEM && ((Item_field*) item)->field->type() == FIELD_TYPE_BIT) item->marker= 4; } } /* We have to create a temporary table to get descriptions of fields (types, sizes and so on). Note that in the table, we first have the ORDER BY fields, then the field list. */ if (!(table= create_tmp_table(thd, tmp_table_param, all_fields, (ORDER*) 0, 0, TRUE, (select_lex->options | thd->variables.option_bits), HA_POS_ERROR, (char*) ""))) DBUG_RETURN(TRUE); table->file->extra(HA_EXTRA_NO_ROWS); table->no_rows= 1; /** Initialize blob_storage if GROUP_CONCAT is used with ORDER BY | DISTINCT and BLOB field count > 0. */ if (order_or_distinct && table->s->blob_fields) table->blob_storage= new Blob_mem_storage(); /* Need sorting or uniqueness: init tree and choose a function to sort. Don't reserve space for NULLs: if any of gconcat arguments is NULL, the row is not added to the result. */ uint tree_key_length= table->s->reclength - table->s->null_bytes; if (arg_count_order) { tree= &tree_base; /* Create a tree for sorting. The tree is used to sort (according to the syntax of this function). If there is no ORDER BY clause, we don't create this tree. */ init_tree(tree, (uint) MY_MIN(thd->variables.max_heap_table_size, thd->variables.sortbuff_size/16), 0, tree_key_length, group_concat_key_cmp_with_order, NULL, (void*) this, MYF(MY_THREAD_SPECIFIC)); } if (distinct) unique_filter= new Unique(group_concat_key_cmp_with_distinct, (void*)this, tree_key_length, ram_limitation(thd)); DBUG_RETURN(FALSE); } /* This is used by rollup to create a separate usable copy of the function */ void Item_func_group_concat::make_unique() { tmp_table_param= 0; table=0; original= 0; force_copy_fields= 1; tree= 0; } String* Item_func_group_concat::val_str(String* str) { DBUG_ASSERT(fixed == 1); if (null_value) return 0; if (no_appended && tree) /* Tree is used for sorting as in ORDER BY */ tree_walk(tree, &dump_leaf_key, this, left_root_right); if (table && table->blob_storage && table->blob_storage->is_truncated_value()) { warning_for_row= true; push_warning_printf(current_thd, Sql_condition::WARN_LEVEL_WARN, ER_CUT_VALUE_GROUP_CONCAT, ER(ER_CUT_VALUE_GROUP_CONCAT), row_count); } return &result; } void Item_func_group_concat::print(String *str, enum_query_type query_type) { str->append(STRING_WITH_LEN("group_concat(")); if (distinct) str->append(STRING_WITH_LEN("distinct ")); for (uint i= 0; i < arg_count_field; i++) { if (i) str->append(','); orig_args[i]->print(str, query_type); } if (arg_count_order) { str->append(STRING_WITH_LEN(" order by ")); for (uint i= 0 ; i < arg_count_order ; i++) { if (i) str->append(','); orig_args[i + arg_count_field]->print(str, query_type); if (order[i]->direction == ORDER::ORDER_ASC) str->append(STRING_WITH_LEN(" ASC")); else str->append(STRING_WITH_LEN(" DESC")); } } str->append(STRING_WITH_LEN(" separator \'")); str->append(*separator); str->append(STRING_WITH_LEN("\')")); } Item_func_group_concat::~Item_func_group_concat() { if (!original && unique_filter) delete unique_filter; }