public static function getTablePrimaryKeys(string $schemaName, string $tableName): array
  {
    $sql = sprintf('
show index from %s.%s
where Key_name = \'PRIMARY\'',
                   $schemaName,
                   $tableName);

    return self::$dl->executeRows($sql);
  }
public static function getTablePrimaryKeys(string $schemaName, string $tableName): array
  {
    $sql = sprintf('
show index from %s.%s
where Key_name = \'PRIMARY\'',
                   $schemaName,
                   $tableName);

    return self::$dl->executeRows($sql);
  }
public static function getTablePrimaryKeys ( string $ schemaName , string $ tableName ) : array { $ sql = sprintf ( '
show index from %s.%s
where Key_name = \'PRIMARY\'' , $ schemaName , $ tableName ) ; return self :: $ dl -> executeRows ( $ sql ) ; }
Selects all primary keys from table.

@param string $schemaName The name of the table schema.
@param string $tableName  The name of the table.

@return array[]
Selects all primary keys from table .