diff options
Diffstat (limited to 'sql/item.cc')
| -rw-r--r-- | sql/item.cc | 64 |
1 files changed, 35 insertions, 29 deletions
diff --git a/sql/item.cc b/sql/item.cc index 0366ea29485..3bc65ca1062 100644 --- a/sql/item.cc +++ b/sql/item.cc @@ -1196,7 +1196,7 @@ bool Item_ref_null_helper::get_date(TIME *ltime, uint fuzzydate) static void mark_as_dependent(THD *thd, SELECT_LEX *last, SELECT_LEX *current, Item_ident *item) { - // store pointer on SELECT_LEX from wich item is dependent + // store pointer on SELECT_LEX from which item is dependent item->depended_from= last; current->mark_as_dependent(last); if (thd->lex->describe & DESCRIBE_EXTENDED) @@ -1872,10 +1872,11 @@ bool Item_field::send(Protocol *protocol, String *buffer) return protocol->store(result_field); } + /* This is used for HAVING clause Find field in select list having the same name - */ +*/ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference) { @@ -1904,8 +1905,9 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference) REPORT_ALL_ERRORS ), ¬_used)) == (Item **)not_found_item) { - upward_lookup= 1; Field *tmp= (Field*) not_found_field; + SELECT_LEX *last= 0; + upward_lookup= 1; /* We can't find table field in select list of current select, consequently we have to find it in outer subselect(s). @@ -1915,7 +1917,6 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference) mention of table name, but if we join tables in one list it will cause error ER_NON_UNIQ_ERROR in find_item_in_list. */ - SELECT_LEX *last=0; for ( ; sl ; sl= (prev_unit= sl->master_unit())->outer_select()) { last= sl; @@ -1967,9 +1968,9 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference) if (!ref) return 1; - else if (!tmp) + if (!tmp) return -1; - else if (ref == (Item **)not_found_item && tmp == not_found_field) + if (ref == (Item **)not_found_item && tmp == not_found_field) { if (upward_lookup) { @@ -1984,31 +1985,33 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference) *(thd->lex->current_select->get_item_list()), &counter, REPORT_ALL_ERRORS, ¬_used); } - ref= 0; + ref= 0; // Safety return 1; } - else if (tmp != not_found_field) + if (tmp != not_found_field) { - ref= 0; // To prevent "delete *ref;" on ~Item_ref() of this item - Item_field* fld= new Item_field(tmp); - if (!fld) + Item_field* fld; + /* + Set ref to 0 as we are replacing this item with the found item + and this will ensure we get an error if this item would be + used elsewhere + */ + ref= 0; // Safety + if (!(fld= new Item_field(tmp))) return 1; thd->change_item_tree(reference, fld); mark_as_dependent(thd, last, thd->lex->current_select, fld); return 0; } - else + if (!(*ref)->fixed) { - if (!(*ref)->fixed) - { - my_error(ER_ILLEGAL_REFERENCE, MYF(0), name, - "forward reference in item list"); - return -1; - } - mark_as_dependent(thd, last, thd->lex->current_select, - this); - ref= last->ref_pointer_array + counter; + my_error(ER_ILLEGAL_REFERENCE, MYF(0), name, + "forward reference in item list"); + return -1; } + mark_as_dependent(thd, last, thd->lex->current_select, + this); + ref= last->ref_pointer_array + counter; } else if (!ref) return 1; @@ -2523,12 +2526,13 @@ bool Item_type_holder::join_types(THD *thd, Item *item) uint32 new_length= real_length(item); bool use_new_field= 0, use_expression_type= 0; Item_result new_result_type= type_convertor[item_type][item->result_type()]; + bool item_is_a_field= item->type() == Item::FIELD_ITEM; /* Check if both items point to fields: in this case we can adjust column types of result table in the union smartly. */ - if (field_example && item->type() == Item::FIELD_ITEM) + if (field_example && item_is_a_field) { Field *field= ((Item_field *)item)->field; /* Can 'field_example' field store data of the column? */ @@ -2545,23 +2549,25 @@ bool Item_type_holder::join_types(THD *thd, Item *item) !is_attr_compatible(this, item)); } } - else if (field_example || item->type() == Item::FIELD_ITEM) + else if (field_example || item_is_a_field) { /* Expression types can't be mixed with field types, we have to use expression types. */ + use_new_field= 1; // make next if test easier use_expression_type= 1; } /* Check whether size/type of the result item should be changed */ - if (use_new_field || use_expression_type || + if (use_new_field || (new_result_type != item_type) || (new_length > max_length) || (!maybe_null && item->maybe_null) || (item_type == STRING_RESULT && !my_charset_same(collation.collation, item->collation.collation))) { - if (use_expression_type || item->type() != Item::FIELD_ITEM) + const char *old_cs,*old_derivation; + if (use_expression_type || !item_is_a_field) field_example= 0; else { @@ -2572,8 +2578,8 @@ bool Item_type_holder::join_types(THD *thd, Item *item) field_example= ((Item_field*) item)->field; } - const char *old_cs= collation.collation->name, - *old_derivation= collation.derivation_name(); + old_cs= collation.collation->name; + old_derivation= collation.derivation_name(); if (item_type == STRING_RESULT && collation.aggregate(item->collation)) { my_error(ER_CANT_AGGREGATE_2COLLATIONS, MYF(0), @@ -2593,12 +2599,12 @@ bool Item_type_holder::join_types(THD *thd, Item *item) return 0; } + uint32 Item_type_holder::real_length(Item *item) { if (item->type() == Item::FIELD_ITEM) - { return ((Item_field *)item)->max_disp_length(); - } + switch (item->result_type()) { case STRING_RESULT: |