选择非空列

SELECT COALESCE(A, CAST(B As varbinary(max)))

更新 :回应评论(谢谢)并假设B是 nvarchar(max) CAST 在里面 COALESCE

尝试 SELECT ISNULL(A, cast(B AS varbinary(max))) FROM TABLE

A = NULL :

CASE A WHEN NULL THEN B ELSE A END

同:

CASE WHEN A = NULL then B ELSE A END

A IS NULL ,例如:

CASE WHEN A IS NULL THEN B ELSE A END

COALESCE(A,B)

两者 when 以及 coalesce 将假定第一个参数的数据类型。将结果转换为 varbinary ,您可以放置 可变长度 列优先,或显式强制转换:

COALESCE(CAST(A AS VARBINARY(MAX)),B)

CREATE TABLE [dbo].[SUPPLIER](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [SUPPLIER_NAME] [varchar](100) NOT NULL,
    [ADDRESS] [varchar](150) NULL,
    [CREATE_DATE] [datetime] NULL,)

    INSERT INTO [MyPayrol].[dbo].[SUPPLIER]
           ([SUPPLIER_NAME]           
           ,[CREATE_DATE])
     VALUES
           ('Khaled Nabil'
           ,GETDATE())


declare @inumberofcolumn int

select @inumberofcolumn= count(*) 
from sys.columns where OBJECT_NAME(object_id) = 'supplier'

declare @nameofcolumn varchar(100)

set @nameofcolumn =''

declare @counter int

set @counter=1


declare @colname varchar(100)

declare @statment varchar(100)

declare @value varchar(100)

while @counter <=@inumberofcolumn
begin

    select @colname= COL_NAME(object_id('[dbo].[SUPPLIER]'),@counter)
    declare @data table ([value] varchar(100))

    --set @statment = 'select '+@colname+' from [dbo].[SUPPLIER]'
      insert @data exec ('SELECT top 1 '+ @colname +' from [dbo].[SUPPLIER]') 
      select @value = [value] from @data
    if @value is not  null
    begin
        if @counter = 1
        begin   
            set @nameofcolumn = @nameofcolumn + @colname
        end
        else
        begin
            set @nameofcolumn = @nameofcolumn + ','+ @colname
        end
    end
    set  @counter = @counter+1
end



execute ('select '+@nameofcolumn+' from [dbo].[SUPPLIER]')