Schema::addUniqueKey
public function Schema::addUniqueKey
public 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.