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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "config.h"
#include <string>
#include "drizzled/foreign_key.h"
#include "drizzled/error.h"
#include "drizzled/create_field.h"
#include "drizzled/internal/my_sys.h"
using namespace drizzled;
extern const CHARSET_INFO *system_charset_info;
Foreign_key::Foreign_key(const Foreign_key &rhs, memory::Root *mem_root)
:Key(rhs),
ref_table(rhs.ref_table),
ref_columns(rhs.ref_columns),
delete_opt(rhs.delete_opt),
update_opt(rhs.update_opt),
match_opt(rhs.match_opt)
{
list_copy_and_replace_each_value(ref_columns, mem_root);
}
/*
Test if a foreign key (= generated key) is a prefix of the given key
(ignoring key name, key type and order of columns)
NOTES:
This is only used to test if an index for a FOREIGN KEY exists
IMPLEMENTATION
We only compare field names
RETURN
0 Generated key is a prefix of other key
1 Not equal
*/
bool foreign_key_prefix(Key *a, Key *b)
{
/* Ensure that 'a' is the generated key */
if (a->generated)
{
if (b->generated && a->columns.elements > b->columns.elements)
std::swap(a, b); // Put shorter key in 'a'
}
else
{
if (!b->generated)
return true; // No foreign key
std::swap(a, b); // Put generated key in 'a'
}
/* Test if 'a' is a prefix of 'b' */
if (a->columns.elements > b->columns.elements)
return true; // Can't be prefix
List_iterator<Key_part_spec> col_it1(a->columns);
List_iterator<Key_part_spec> col_it2(b->columns);
const Key_part_spec *col1, *col2;
#ifdef ENABLE_WHEN_INNODB_CAN_HANDLE_SWAPED_FOREIGN_KEY_COLUMNS
while ((col1= col_it1++))
{
bool found= 0;
col_it2.rewind();
while ((col2= col_it2++))
{
if (*col1 == *col2)
{
found= true;
break;
}
}
if (!found)
return true; // Error
}
return false; // Is prefix
#else
while ((col1= col_it1++))
{
col2= col_it2++;
if (!(*col1 == *col2))
return true;
}
return false; // Is prefix
#endif
}
/*
Check if the foreign key options are compatible with columns
on which the FK is created.
RETURN
0 Key valid
1 Key invalid
*/
bool Foreign_key::validate(List<CreateField> &table_fields)
{
CreateField *sql_field;
Key_part_spec *column;
List_iterator<Key_part_spec> cols(columns);
List_iterator<CreateField> it(table_fields);
while ((column= cols++))
{
it.rewind();
while ((sql_field= it++) &&
my_strcasecmp(system_charset_info,
column->field_name.str,
sql_field->field_name)) {}
if (!sql_field)
{
my_error(ER_KEY_COLUMN_DOES_NOT_EXITS, MYF(0), column->field_name.str);
return true;
}
}
return false;
}
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