Обединете няколко реда в един ред

Ето А начин да го направите (работи и с 2005):

Таблица

DECLARE @table TABLE
    (
      [Type_ID] INT,
      [Client_ID] VARCHAR(50),
      [PBX_Vendor] VARCHAR(50)
    )

Данни

INSERT  INTO @table
        SELECT  127,
                '090820006311404926326C',
                'Aastra'
        UNION ALL
        SELECT  127,
                '090820006311404926326C',
                'Ericsson'
        UNION ALL
        SELECT  127,
                '111012237401404926326C',
                'Aastra'
        UNION ALL
        SELECT  127,
                '120209287521404926326C',
                'Aastra'
        UNION ALL
        SELECT  127,
                '120209287521404926326C',
                'Alcatel'

Запитване

SELECT  [Type_ID],
        [Client_ID],
        (
          SELECT    STUFF((
                            SELECT  ',' + [PBX_Vendor]
                            FROM    @table
                            WHERE   [Client_ID] = tbl.[Client_ID]
                                    AND [Type_ID] = tbl.[Type_ID]
                            GROUP BY [PBX_Vendor]
                            ORDER BY [PBX_Vendor]
                          FOR
                            XML PATH('')
                          ), 1, 1, '')
        ) PBX_Vendor
FROM    @table tbl
GROUP BY [Type_ID],
        [Client_ID]

Резултат

Type_ID     Client_ID               PBX_Vendor
127         090820006311404926326C  Aastra,Ericsson
127         111012237401404926326C  Aastra
127         120209287521404926326C  Aastra,Alcatel