public function DatabaseSchema_mysql::addUniqueKey in Drupal 7

Add a unique key.

Parameters

$table: The table to be altered.

$name: The name of the key.

$fields: An array of field names.

Throws

DatabaseSchemaObjectDoesNotExistException If the specified table doesn't exist.

DatabaseSchemaObjectExistsException If the specified table already has a key by that name.

Overrides DatabaseSchema::addUniqueKey

File

includes/database/mysql/schema.inc, line 425

Database schema code for MySQL database servers.

Class

DatabaseSchema_mysql

Code

public function addUniqueKey($table, $name, $fields) {
  if (!$this
    ->tableExists($table)) {
    throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add unique key @name to table @table: table doesn't exist.", array(
      '@table' => $table,
      '@name' => $name,
    )));
  }
  if ($this
    ->indexExists($table, $name)) {
    throw new DatabaseSchemaObjectExistsException(t("Cannot add unique key @name to table @table: unique key already exists.", array(
      '@table' => $table,
      '@name' => $name,
    )));
  }
  $this->connection
    ->query('ALTER TABLE {' . $table . '} ADD UNIQUE KEY `' . $name . '` (' . $this
    ->createKeySql($fields) . ')');
}