+------------+----------+
    |IndexKey    | UserName |
    +----------- +----------+
    | -1         |  ყველა   |
    +-----------------------+

+-----------+----------+
    |IndexKey   | Name     |
    +-----------+----------+
    | 1         |  თედო   |
    +-----------+----------+
    | 2         |  თორნიკე |
    +-----------+----------+
    | 4         |  გელა    |
    +----------------------+

+-----------+----------+
    |-1         |  ყველა   |
    +-----------+----------+
    | 1         |  თედო   |
    +-----------+----------+
    | 2         |  თორნიკე |
    +-----------+----------+
    | 4         |  გელა    |
    +----------------------+

SELECT *
FROM AllUsers
UNION ALL
SELECT dbo_NGAC_USERINFO.IndexKey, dbo_NGAC_USERINFO.Name
FROM dbo_NGAC_USERINFO