diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 266 |
1 files changed, 163 insertions, 103 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index bfe17bb43e1..34da8639d9a 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -142,10 +142,10 @@ static void update_depend_map_for_order(JOIN *join, ORDER *order); static ORDER *remove_const(JOIN *join,ORDER *first_order,COND *cond, bool change_list, bool *simple_order); static int return_zero_rows(JOIN *join, select_result *res, - List<TABLE_LIST> &tables, - List<Item> &fields, bool send_row, + List<TABLE_LIST> *tables, + List<Item> *fields, bool send_row, ulonglong select_options, const char *info, - Item *having, List<Item> &all_fields); + Item *having, List<Item> *all_fields); static COND *build_equal_items(JOIN *join, COND *cond, COND_EQUAL *inherited, List<TABLE_LIST> *join_list, @@ -1157,11 +1157,40 @@ int SELECT_LEX::vers_setup_conds(THD *thd, TABLE_LIST *tables) DBUG_RETURN(0); } + /***************************************************************************** Check fields, find best join, do the select and output fields. mysql_select assumes that all tables are already opened *****************************************************************************/ +/* + Check if we have a field reference. If yes, we have to use + mixed_implicit_grouping. +*/ + +static bool check_list_for_field(List<Item> *items) +{ + List_iterator_fast <Item> select_it(*items); + Item *select_el; + + while ((select_el= select_it++)) + { + if (select_el->with_field) + return true; + } + return false; +} + +static bool check_list_for_field(ORDER *order) +{ + for (; order; order= order->next) + { + if (order->item[0]->with_field) + return true; + } + return false; +} + /** Prepare of whole select (including sub queries in future). @@ -1241,53 +1270,45 @@ JOIN::prepare(TABLE_LIST *tables_init, DBUG_RETURN(-1); /* - TRUE if the SELECT list mixes elements with and without grouping, - and there is no GROUP BY clause. Mixing non-aggregated fields with - aggregate functions in the SELECT list is a MySQL extenstion that - is allowed only if the ONLY_FULL_GROUP_BY sql mode is not set. + mixed_implicit_grouping will be set to TRUE if the SELECT list + mixes elements with and without grouping, and there is no GROUP BY + clause. + Mixing non-aggregated fields with aggregate functions in the + SELECT list or HAVING is a MySQL extension that is allowed only if + the ONLY_FULL_GROUP_BY sql mode is not set. */ mixed_implicit_grouping= false; if ((~thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY) && select_lex->with_sum_func && !group_list) { - List_iterator_fast <Item> select_it(fields_list); - Item *select_el; /* Element of the SELECT clause, can be an expression. */ - bool found_field_elem= false; - bool found_sum_func_elem= false; - - while ((select_el= select_it++)) + if (check_list_for_field(&fields_list) || + check_list_for_field(order)) { - if (select_el->with_sum_func()) - found_sum_func_elem= true; - if (select_el->with_field) - found_field_elem= true; - if (found_sum_func_elem && found_field_elem) + TABLE_LIST *tbl; + List_iterator_fast<TABLE_LIST> li(select_lex->leaf_tables); + + mixed_implicit_grouping= true; // mark for future + + while ((tbl= li++)) { - mixed_implicit_grouping= true; - break; + /* + If the query uses implicit grouping where the select list + contains both aggregate functions and non-aggregate fields, + any non-aggregated field may produce a NULL value. Set all + fields of each table as nullable before semantic analysis to + take into account this change of nullability. + + Note: this loop doesn't touch tables inside merged + semi-joins, because subquery-to-semijoin conversion has not + been done yet. This is intended. + */ + if (tbl->table) + tbl->table->maybe_null= 1; } } } - table_count= select_lex->leaf_tables.elements; - TABLE_LIST *tbl; - List_iterator_fast<TABLE_LIST> li(select_lex->leaf_tables); - while ((tbl= li++)) - { - /* - If the query uses implicit grouping where the select list contains both - aggregate functions and non-aggregate fields, any non-aggregated field - may produce a NULL value. Set all fields of each table as nullable before - semantic analysis to take into account this change of nullability. - - Note: this loop doesn't touch tables inside merged semi-joins, because - subquery-to-semijoin conversion has not been done yet. This is intended. - */ - if (mixed_implicit_grouping && tbl->table) - tbl->table->maybe_null= 1; - } - uint real_og_num= og_num; if (skip_order_by && select_lex != select_lex->master_unit()->global_parameters()) @@ -3838,7 +3859,7 @@ bool JOIN::make_aggr_tables_info() set_items_ref_array(items0); if (join_tab) join_tab[exec_join_tab_cnt() + aggr_tables - 1].next_select= - setup_end_select_func(this, NULL); + setup_end_select_func(this); group= has_group_by; DBUG_RETURN(false); @@ -4220,13 +4241,7 @@ JOIN::reinit() } } - /* Reset of sum functions */ - if (sum_funcs) - { - Item_sum *func, **func_ptr= sum_funcs; - while ((func= *(func_ptr++))) - func->clear(); - } + clear_sum_funcs(); if (no_rows_in_result_called) { @@ -4510,12 +4525,12 @@ void JOIN::exec_inner() } else { - (void) return_zero_rows(this, result, select_lex->leaf_tables, - *columns_list, + (void) return_zero_rows(this, result, &select_lex->leaf_tables, + columns_list, send_row_on_empty_set(), select_options, zero_result_cause, - having ? having : tmp_having, all_fields); + having ? having : tmp_having, &all_fields); DBUG_VOID_RETURN; } } @@ -14642,10 +14657,36 @@ ORDER *simple_remove_const(ORDER *order, COND *where) } +/* + Set all fields in the table to have a null value + + @param tables Table list +*/ + +static void make_tables_null_complemented(List<TABLE_LIST> *tables) +{ + List_iterator<TABLE_LIST> ti(*tables); + TABLE_LIST *table; + while ((table= ti++)) + { + /* + Don't touch semi-join materialization tables, as the a join_free() + call may have freed them (and HAVING clause can't have references to + them anyway). + */ + if (!table->is_jtbm()) + { + TABLE *tbl= table->table; + mark_as_null_row(tbl); // Set fields to NULL + } + } +} + + static int -return_zero_rows(JOIN *join, select_result *result, List<TABLE_LIST> &tables, - List<Item> &fields, bool send_row, ulonglong select_options, - const char *info, Item *having, List<Item> &all_fields) +return_zero_rows(JOIN *join, select_result *result, List<TABLE_LIST> *tables, + List<Item> *fields, bool send_row, ulonglong select_options, + const char *info, Item *having, List<Item> *all_fields) { DBUG_ENTER("return_zero_rows"); @@ -14661,24 +14702,15 @@ return_zero_rows(JOIN *join, select_result *result, List<TABLE_LIST> &tables, Set all tables to have NULL row. This is needed as we will be evaluating HAVING condition. */ - List_iterator<TABLE_LIST> ti(tables); - TABLE_LIST *table; - while ((table= ti++)) - { - /* - Don't touch semi-join materialization tables, as the above join_free() - call has freed them (and HAVING clause can't have references to them - anyway). - */ - if (!table->is_jtbm()) - mark_as_null_row(table->table); // All fields are NULL - } - List_iterator_fast<Item> it(all_fields); + make_tables_null_complemented(tables); + + List_iterator_fast<Item> it(*all_fields); Item *item; /* Inform all items (especially aggregating) to calculate HAVING correctly, also we will need it for sending results. */ + join->no_rows_in_result_called= 1; while ((item= it++)) item->no_rows_in_result(); if (having && having->val_int() == 0) @@ -14692,12 +14724,12 @@ return_zero_rows(JOIN *join, select_result *result, List<TABLE_LIST> &tables, join->thd->limit_found_rows= 0; } - if (!(result->send_result_set_metadata(fields, + if (!(result->send_result_set_metadata(*fields, Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF))) { bool send_error= FALSE; if (send_row) - send_error= result->send_data(fields) > 0; + send_error= result->send_data(*fields) > 0; if (likely(!send_error)) result->send_eof(); // Should be safe } @@ -14713,49 +14745,42 @@ return_zero_rows(JOIN *join, select_result *result, List<TABLE_LIST> &tables, } /** - used only in JOIN::clear (always) and in do_select() - (if there where no matching rows) + Reset table rows to contain a null-complement row (all fields are null) + + Used only in JOIN::clear() and in do_select() if there where no matching rows. @param join JOIN - @param cleared_tables If not null, clear also const tables and mark all - cleared tables in the map. cleared_tables is only - set when called from do_select() when there is a - group function and there where no matching rows. + @param cleared_tables Used to mark all cleared tables in the map. Needed for + unclear_tables() to know which tables to restore to + their original state. */ static void clear_tables(JOIN *join, table_map *cleared_tables) { - /* - must clear only the non-const tables as const tables are not re-calculated. - */ + DBUG_ASSERT(cleared_tables); for (uint i= 0 ; i < join->table_count ; i++) { TABLE *table= join->table[i]; if (table->null_row) continue; // Nothing more to do - if (!(table->map & join->const_table_map) || cleared_tables) + (*cleared_tables)|= (((table_map) 1) << i); + if (table->s->null_bytes) { - if (cleared_tables) - { - (*cleared_tables)|= (((table_map) 1) << i); - if (table->s->null_bytes) - { - /* - Remember null bits for the record so that we can restore the - original const record in unclear_tables() - */ - memcpy(table->record[1], table->null_flags, table->s->null_bytes); - } - } - mark_as_null_row(table); // All fields are NULL + /* + Remember null bits for the record so that we can restore the + original const record in unclear_tables() + */ + memcpy(table->record[1], table->null_flags, table->s->null_bytes); } + mark_as_null_row(table); // All fields are NULL } } /** Reverse null marking for tables and restore null bits. + This return the tables to the state of before clear_tables(). We have to do this because the tables may be re-used in a sub query and the subquery will assume that the const tables contains the original @@ -20235,9 +20260,9 @@ void set_postjoin_aggr_write_func(JOIN_TAB *tab) end_select function to use. This function can't fail. */ -Next_select_func setup_end_select_func(JOIN *join, JOIN_TAB *tab) +Next_select_func setup_end_select_func(JOIN *join) { - TMP_TABLE_PARAM *tmp_tbl= tab ? tab->tmp_table_param : &join->tmp_table_param; + TMP_TABLE_PARAM *tmp_tbl= &join->tmp_table_param; /* Choose method for presenting result to user. Use end_send_group @@ -20308,7 +20333,7 @@ do_select(JOIN *join, Procedure *procedure) join->duplicate_rows= join->send_records=0; if (join->only_const_tables() && !join->need_tmp) { - Next_select_func end_select= setup_end_select_func(join, NULL); + Next_select_func end_select= setup_end_select_func(join); /* HAVING will be checked after processing aggregate functions, @@ -20793,6 +20818,7 @@ sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records) } } + /* Restore state if mark_as_null_row() have been called */ if (join_tab->last_inner) { JOIN_TAB *last_inner_tab= join_tab->last_inner; @@ -22155,11 +22181,18 @@ end_send_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), { int idx= -1; enum_nested_loop_state ok_code= NESTED_LOOP_OK; + /* + join_tab can be 0 in the case all tables are const tables and we did not + need a temporary table to store the result. + In this case we use the original given fields, which is stored in + join->fields. + */ List<Item> *fields= join_tab ? (join_tab-1)->fields : join->fields; DBUG_ENTER("end_send_group"); if (!join->items3.is_null() && !join->set_group_rpa) { + /* Move ref_pointer_array to points to items3 */ join->set_group_rpa= true; join->set_items_ref_array(join->items3); } @@ -22167,10 +22200,12 @@ end_send_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), if (!join->first_record || end_of_records || (idx=test_if_group_changed(join->group_fields)) >= 0) { + if (!join->group_sent && (join->first_record || (end_of_records && !join->group && !join->group_optimized_away))) { + table_map cleared_tables= (table_map) 0; if (join->procedure) join->procedure->end_group(); if (idx < (int) join->send_group_parts) @@ -22193,11 +22228,13 @@ end_send_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), { if (!join->first_record) { - List_iterator_fast<Item> it(*join->fields); - Item *item; /* No matching rows for group function */ - join->clear(); + List_iterator_fast<Item> it(*fields); + Item *item; + join->no_rows_in_result_called= 1; + + join->clear(&cleared_tables); while ((item= it++)) item->no_rows_in_result(); } @@ -22223,7 +22260,14 @@ end_send_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), if (join->rollup_send_data((uint) (idx+1))) error= 1; } - } + if (join->no_rows_in_result_called) + { + /* Restore null tables to original state */ + join->no_rows_in_result_called= 0; + if (cleared_tables) + unclear_tables(join, &cleared_tables); + } + } if (unlikely(error > 0)) DBUG_RETURN(NESTED_LOOP_ERROR); /* purecov: inspected */ if (end_of_records) @@ -22525,6 +22569,7 @@ end_write_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), { if (join->first_record || (end_of_records && !join->group)) { + table_map cleared_tables= (table_map) 0; if (join->procedure) join->procedure->end_group(); int send_group_parts= join->send_group_parts; @@ -22533,7 +22578,7 @@ end_write_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), if (!join->first_record) { /* No matching rows for group function */ - join->clear(); + join->clear(&cleared_tables); } copy_sum_funcs(join->sum_funcs, join->sum_funcs_end[send_group_parts]); @@ -22556,6 +22601,8 @@ end_write_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), DBUG_RETURN(NESTED_LOOP_ERROR); } } + if (cleared_tables) + unclear_tables(join, &cleared_tables); if (end_of_records) goto end; } @@ -26658,11 +26705,8 @@ int JOIN::rollup_write_data(uint idx, TMP_TABLE_PARAM *tmp_table_param_arg, TABL (end_send_group/end_write_group) */ -void JOIN::clear() +void inline JOIN::clear_sum_funcs() { - clear_tables(this, 0); - copy_fields(&tmp_table_param); - if (sum_funcs) { Item_sum *func, **func_ptr= sum_funcs; @@ -26672,6 +26716,22 @@ void JOIN::clear() } +/* + Prepare for returning 'empty row' when there is no matching row. + + - Mark all tables with mark_as_null_row() + - Make a copy of of all simple SELECT items + - Reset all sum functions to NULL or 0. +*/ + +void JOIN::clear(table_map *cleared_tables) +{ + clear_tables(this, cleared_tables); + copy_fields(&tmp_table_param); + clear_sum_funcs(); +} + + /** Print an EXPLAIN line with all NULLs and given message in the 'Extra' column @@ -28138,7 +28198,7 @@ void st_select_lex::print_set_clause(THD *thd, String *str, else str->append(','); - item->print(str, query_type); + item->print(str, (enum_query_type) (query_type | QT_NO_DATA_EXPANSION)); str->append(STRING_WITH_LEN(" = ")); val->print(str, query_type); } |