function Schema::addUniqueKey

Schema::addUniqueKey($table, $name, $fields)

Add a unique key.

Parameters

$table: The table to be altered.

$name: The name of the key.

$fields: An array of field names.

Throws

\Drupal\Core\Database\SchemaObjectDoesNotExistException If the specified table doesn't exist.

\Drupal\Core\Database\SchemaObjectExistsException If the specified table already has a key by that name.

Overrides Schema::addUniqueKey

File

core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php, line 637

Class

Schema

PostgreSQL implementation of \Drupal\Core\Database\Schema.

Namespace

Drupal\Core\Database\Driver\pgsql

Code

function addUniqueKey($table, $name, $fields) {
  if (!$this->tableExists($table)) {
    throw new SchemaObjectDoesNotExistException(t("Cannot add unique key @name to table @table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
  }
  if ($this->constraintExists($table, $name . '__key')) {
    throw new SchemaObjectExistsException(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 CONSTRAINT ' . $this->ensureIdentifiersLength($table, $name, 'key') . ' UNIQUE (' . implode(',', $fields) . ')');
  $this->resetTableInformation($table);
}