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/* Copyright (C) 2000 MySQL AB
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#include "mysql_priv.h"
/*
Row items used for comparing rows and IN operations on rows:
(a, b, c) > (10, 10, 30)
(a, b, c) = (select c, d, e, from t1 where x=12)
(a, b, c) IN ((1,2,2), (3,4,5), (6,7,8)
(a, b, c) IN (select c, d, e, from t1)
*/
Item_row::Item_row(List<Item> &arg):
Item(), used_tables_cache(0), const_item_cache(1), with_null(0)
{
//TODO: think placing 2-3 component items in item (as it done for function)
if ((arg_count= arg.elements))
items= (Item**) sql_alloc(sizeof(Item*)*arg_count);
else
items= 0;
List_iterator<Item> li(arg);
uint i= 0;
Item *item;
while ((item= li++))
{
items[i]= item;
i++;
}
}
void Item_row::illegal_method_call(const char *method)
{
DBUG_ENTER("Item_row::illegal_method_call");
DBUG_PRINT("error", ("!!! %s method was called for row item", method));
DBUG_ASSERT(0);
my_error(ER_OPERAND_COLUMNS, MYF(0), 1);
DBUG_VOID_RETURN;
}
bool Item_row::fix_fields(THD *thd, Item **ref)
{
DBUG_ASSERT(fixed == 0);
null_value= 0;
maybe_null= 0;
Item **arg, **arg_end;
for (arg= items, arg_end= items+arg_count; arg != arg_end ; arg++)
{
if ((*arg)->fix_fields(thd, arg))
return TRUE;
// we can't assign 'item' before, because fix_fields() can change arg
Item *item= *arg;
used_tables_cache |= item->used_tables();
const_item_cache&= item->const_item() && !with_null;
if (const_item_cache)
{
if (item->cols() > 1)
with_null|= item->null_inside();
else
{
if (item->is_null())
with_null|= 1;
}
}
maybe_null|= item->maybe_null;
with_sum_func= with_sum_func || item->with_sum_func;
}
fixed= 1;
return FALSE;
}
void Item_row::cleanup()
{
DBUG_ENTER("Item_row::cleanup");
Item::cleanup();
/* Reset to the original values */
used_tables_cache= 0;
const_item_cache= 1;
with_null= 0;
DBUG_VOID_RETURN;
}
void Item_row::split_sum_func(THD *thd, Item **ref_pointer_array,
List<Item> &fields)
{
Item **arg, **arg_end;
for (arg= items, arg_end= items+arg_count; arg != arg_end ; arg++)
(*arg)->split_sum_func2(thd, ref_pointer_array, fields, arg, TRUE);
}
void Item_row::update_used_tables()
{
used_tables_cache= 0;
const_item_cache= 1;
for (uint i= 0; i < arg_count; i++)
{
items[i]->update_used_tables();
used_tables_cache|= items[i]->used_tables();
const_item_cache&= items[i]->const_item();
}
}
bool Item_row::check_cols(uint c)
{
if (c != arg_count)
{
my_error(ER_OPERAND_COLUMNS, MYF(0), c);
return 1;
}
return 0;
}
void Item_row::print(String *str)
{
str->append('(');
for (uint i= 0; i < arg_count; i++)
{
if (i)
str->append(',');
items[i]->print(str);
}
str->append(')');
}
bool Item_row::walk(Item_processor processor, byte *arg)
{
for (uint i= 0; i < arg_count; i++)
{
if (items[i]->walk(processor, arg))
return 1;
}
return (this->*processor)(arg);
}
Item *Item_row::transform(Item_transformer transformer, byte *arg)
{
DBUG_ASSERT(!current_thd->is_stmt_prepare());
for (uint i= 0; i < arg_count; i++)
{
Item *new_item= items[i]->transform(transformer, arg);
if (!new_item)
return 0;
/*
THD::change_item_tree() should be called only if the tree was
really transformed, i.e. when a new item has been created.
Otherwise we'll be allocating a lot of unnecessary memory for
change records at each execution.
*/
if (items[i] != new_item)
current_thd->change_item_tree(&items[i], new_item);
}
return (this->*transformer)(arg);
}
void Item_row::bring_value()
{
for (uint i= 0; i < arg_count; i++)
items[i]->bring_value();
}
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