SQL：如何把多行查询结果，作为一行返回

CREATE    FUNCTION dbo.UF_GetInvoiceSerials( @bizCode VARCHAR(10))
   RETURNS VARCHAR(100)
AS
BEGIN
   DECLARE @ret AS VARCHAR(1000)
   SELECT @ret=Coalesce(@ret + ', ','') +
         CASE e.ID
               WHEN '1' THEN c.InvoiceNo
               WHEN '2' THEN d.ExpenseNO
               ELSE 'N/A'
          END
   from   dbo.Business a WITH(NOLOCK)
          LEFT  JOIN dbo.Asset_Card b WITH(NOLOCK)
               ON  b.BusinessID = a.ID
          LEFT  JOIN dbo.Equipment_Card c WITH(NOLOCK)
               ON  c.Asset_CardID = b.ID
          LEFT JOIN dbo.FurnitureCard d WITH(NOLOCK)
               ON  d.Asset_CardID = b.ID
          LEFT JOIN dbo.Assert_Type e WITH(NOLOCK)
               ON  e.ID = b.Assert_TypeID
        WHERE a.BusinessCode=@bizCode
   RETURN Isnull(@ret,'N/A')
END
 
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