public function getPrimaryKey($table)
    {
        if (! $table) {
            return '';
        }

        $sql = "SELECT cols.column_name
            FROM all_constraints cons, all_cons_columns cols
            WHERE upper(cols.table_name) = upper('{$table}')
                AND cons.constraint_type = 'P'
                AND cons.constraint_name = cols.constraint_name
                AND cons.owner = cols.owner
                AND cols.position = 1
                AND cons.owner = (select user from dual)
            ORDER BY cols.table_name, cols.position";
        $data = $this->connection->selectOne($sql);

        if ($data) {
            return $data->column_name;
        }

        return '';
    }
public function getPrimaryKey($table)
    {
        if (! $table) {
            return '';
        }

        $sql = "SELECT cols.column_name
            FROM all_constraints cons, all_cons_columns cols
            WHERE upper(cols.table_name) = upper('{$table}')
                AND cons.constraint_type = 'P'
                AND cons.constraint_name = cols.constraint_name
                AND cons.owner = cols.owner
                AND cols.position = 1
                AND cons.owner = (select user from dual)
            ORDER BY cols.table_name, cols.position";
        $data = $this->connection->selectOne($sql);

        if ($data) {
            return $data->column_name;
        }

        return '';
    }
public function getPrimaryKey ( $ table ) { if ( ! $ table ) { return '' ; } $ sql = "SELECT cols.column_name
            FROM all_constraints cons, all_cons_columns cols
            WHERE upper(cols.table_name) = upper('{$table}')
                AND cons.constraint_type = 'P'
                AND cons.constraint_name = cols.constraint_name
                AND cons.owner = cols.owner
                AND cols.position = 1
                AND cons.owner = (select user from dual)
            ORDER BY cols.table_name, cols.position" ; $ data = $ this -> connection -> selectOne ( $ sql ) ; if ( $ data ) { return $ data -> column_name ; } return '' ; }
Get table's primary key.

@param  string $table
@return string
Get table s primary key .