Unisci più righe in un'unica riga

Ecco A modo di farlo (funziona anche con 2005):

Tabella

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

Dati

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'

Interroga

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]

Risultato

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