Add a unique key.
$table: The table to be altered.
$name: The name of the key.
$fields: An array of field names.
DatabaseSchemaObjectDoesNotExistException If the specified table doesn't exist.
DatabaseSchemaObjectExistsException If the specified table already has a key by that name.
Overrides DatabaseSchema::addUniqueKey
public function addUniqueKey($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,
)));
}
$schema['unique keys'][$name] = $fields;
$statements = $this
->createIndexSql($table, $schema);
foreach ($statements as $statement) {
$this->connection
->query($statement);
}
}