database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-29 05:21:33 +03:00
Code Activity

Merge next-mr -> next-4284.

Browse Source
This commit is contained in:
Konstantin Osipov
2009-12-15 22:59:07 +03:00
parent 5e57d0916c 408dd52a6a
commit e931ef415a
69 changed files with 951 additions and 215 deletions
Download Patch File Download Diff File Expand all files Collapse all files

154
sql/sql_select.cc
View File

@ -9159,18 +9159,26 @@ optimize_cond(JOIN *join, COND *conds, List<TABLE_LIST> *join_list,
/**
Remove const and eq items.
Handles the reqursive job for remove_eq_conds()
@return
Return new item, or NULL if no condition @n
cond_value is set to according:
- COND_OK : query is possible (field = constant)
- COND_TRUE : always true ( 1 = 1 )
- COND_FALSE : always false ( 1 = 2 )
Remove const and eq items. Return new item, or NULL if no condition
cond_value is set to according:
COND_OK query is possible (field = constant)
COND_TRUE always true ( 1 = 1 )
COND_FALSE always false ( 1 = 2 )
SYNPOSIS
remove_eq_conds()
thd THD environment
cond the condition to handle
cond_value the resulting value of the condition
RETURN
*COND with the simplified condition
*/
COND *
remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
static COND *
internal_remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
{
if (cond->type() == Item::COND_ITEM)
{
@ -9184,7 +9192,7 @@ remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
Item *item;
while ((item=li++))
{
Item *new_item=remove_eq_conds(thd, item, &tmp_cond_value);
Item *new_item=internal_remove_eq_conds(thd, item, &tmp_cond_value);
if (!new_item)
li.remove();
else if (item != new_item)
@ -9232,6 +9240,86 @@ remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
}
else if (cond->type() == Item::FUNC_ITEM &&
((Item_func*) cond)->functype() == Item_func::ISNULL_FUNC)
{
Item_func_isnull *func=(Item_func_isnull*) cond;
Item **args= func->arguments();
if (args[0]->type() == Item::FIELD_ITEM)
{
Field *field=((Item_field*) args[0])->field;
/* fix to replace 'NULL' dates with '0' (shreeve@uci.edu) */
/*
datetime_field IS NULL has to be modified to
datetime_field == 0
*/
if (((field->type() == MYSQL_TYPE_DATE) ||
(field->type() == MYSQL_TYPE_DATETIME)) &&
(field->flags & NOT_NULL_FLAG) && !field->table->maybe_null)
{
COND *new_cond;
if ((new_cond= new Item_func_eq(args[0],new Item_int("0", 0, 2))))
{
cond=new_cond;
/*
Item_func_eq can't be fixed after creation so we do not check
cond->fixed, also it do not need tables so we use 0 as second
argument.
*/
cond->fix_fields(thd, &cond);
}
}
}
if (cond->const_item())
{
*cond_value= eval_const_cond(cond) ? Item::COND_TRUE : Item::COND_FALSE;
return (COND*) 0;
}
}
else if (cond->const_item())
{
*cond_value= eval_const_cond(cond) ? Item::COND_TRUE : Item::COND_FALSE;
return (COND*) 0;
}
else if ((*cond_value= cond->eq_cmp_result()) != Item::COND_OK)
{ // boolan compare function
Item *left_item= ((Item_func*) cond)->arguments()[0];
Item *right_item= ((Item_func*) cond)->arguments()[1];
if (left_item->eq(right_item,1))
{
if (!left_item->maybe_null ||
((Item_func*) cond)->functype() == Item_func::EQUAL_FUNC)
return (COND*) 0; // Compare of identical items
}
}
*cond_value=Item::COND_OK;
return cond; // Point at next and level
}
/**
Remove const and eq items. Return new item, or NULL if no condition
cond_value is set to according:
COND_OK query is possible (field = constant)
COND_TRUE always true ( 1 = 1 )
COND_FALSE always false ( 1 = 2 )
SYNPOSIS
remove_eq_conds()
thd THD environment
cond the condition to handle
cond_value the resulting value of the condition
NOTES
calls the inner_remove_eq_conds to check all the tree reqursively
RETURN
*COND with the simplified condition
*/
COND *
remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
{
if (cond->type() == Item::FUNC_ITEM &&
((Item_func*) cond)->functype() == Item_func::ISNULL_FUNC)
{
/*
Handles this special case for some ODBC applications:
@ -9275,52 +9363,16 @@ remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
clear for next row
*/
thd->substitute_null_with_insert_id= FALSE;
}
/* fix to replace 'NULL' dates with '0' (shreeve@uci.edu) */
else if (((field->type() == MYSQL_TYPE_DATE) ||
(field->type() == MYSQL_TYPE_DATETIME)) &&
(field->flags & NOT_NULL_FLAG) &&
!field->table->maybe_null)
{
COND *new_cond;
if ((new_cond= new Item_func_eq(args[0],new Item_int("0", 0, 2))))
{
cond=new_cond;
/*
Item_func_eq can't be fixed after creation so we do not check
cond->fixed, also it do not need tables so we use 0 as second
argument.
*/
cond->fix_fields(thd, &cond);
}
*cond_value= Item::COND_OK;
return cond;
}
}
if (cond->const_item())
{
*cond_value= eval_const_cond(cond) ? Item::COND_TRUE : Item::COND_FALSE;
return (COND*) 0;
}
}
else if (cond->const_item())
{
*cond_value= eval_const_cond(cond) ? Item::COND_TRUE : Item::COND_FALSE;
return (COND*) 0;
}
else if ((*cond_value= cond->eq_cmp_result()) != Item::COND_OK)
{ // boolan compare function
Item *left_item= ((Item_func*) cond)->arguments()[0];
Item *right_item= ((Item_func*) cond)->arguments()[1];
if (left_item->eq(right_item,1))
{
if (!left_item->maybe_null ||
((Item_func*) cond)->functype() == Item_func::EQUAL_FUNC)
return (COND*) 0; // Compare of identical items
}
}
*cond_value=Item::COND_OK;
return cond; // Point at next and level
return internal_remove_eq_conds(thd, cond, cond_value); // Scan all the condition
}
/*
Check if equality can be used in removing components of GROUP BY/DISTINCT