diff options
Diffstat (limited to 'sql/sql_update.cc')
| -rw-r--r-- | sql/sql_update.cc | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/sql/sql_update.cc b/sql/sql_update.cc index b6bce800b0e..cb8064bef87 100644 --- a/sql/sql_update.cc +++ b/sql/sql_update.cc @@ -70,7 +70,7 @@ int mysql_update(THD *thd, ha_rows updated, found; key_map old_used_keys; TABLE *table; - SQL_SELECT *select; + SQL_SELECT *select= 0; READ_RECORD info; TABLE_LIST *update_table_list= ((TABLE_LIST*) thd->lex->select_lex.table_list.first); @@ -131,11 +131,19 @@ int mysql_update(THD *thd, DBUG_RETURN(-1); /* purecov: inspected */ } + if (conds) + { + Item::cond_result cond_value; + conds= remove_eq_conds(thd, conds, &cond_value); + if (cond_value == Item::COND_FALSE) + limit= 0; // Impossible WHERE + } // Don't count on usage of 'only index' when calculating which key to use table->used_keys.clear_all(); - select=make_select(table,0,0,conds,&error); - if (error || - (select && select->check_quick(thd, safe_update, limit)) || !limit) + if (limit) + select=make_select(table,0,0,conds,&error); + if (error || !limit || + (select && select->check_quick(thd, safe_update, limit))) { delete select; free_underlaid_joins(thd, &thd->lex->select_lex); |