用随机整数填充所有列

我试图用一些随机整数填充3列所有行。
以下代码有错误

“@上限附近语法不正确。应为(或选择

我做错了什么?

---- Create the variables for the random number generation
DECLARE @Random INT;
DECLARE @Upper INT;
DECLARE @Lower INT

---- Create a random number between 1 and 111
SET @Lower = 1   -- The lowest random number
SET @Upper = 111 -- The highest random number

UPDATE [tblProject]
SET 
       [ContractorID1] = @Random = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0) -- error
      ,[ContractorID2] = @Random = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0) -- error
      ,[ContractorID3] = @Random = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0) -- error