sql-server-2008 - 字符串值应增加 1

Question

显示的代码不增加 1，所有记录都显示相同的字符串值。

DECLARE @q_id  NVARCHAR(50)
begin 

SET @q_id='JEE_PHY_1' 

UPDATE oems_question7  SET q_id = SUBSTRING (@q_id ,0,CHARINDEX('_', @q_id,5) + 1 ) + ' ' + CONVERT(NVARCHAR,CONVERT(INT, SUBSTRING ( @q_id ,CHARINDEX('_', @q_id,5) + 1, LEN(@q_id) )) +1)
WHERE id between 1 and 40

end

Answer 1

使用您的代码，您将使用完全相同的值更新所有行。您应该应用 ROW_NUMBER 给每一行一个不同的递增数字，然后更新这些行。

DECLARE @q_id  NVARCHAR(50)
begin 

SET @q_id='JEE_PHY_1' 

;WITH UpdateCTE AS
(
    SELECT q_id,
           ROW_NUMBER() OVER(ORDER BY q_id) AS RowNum
    FROM   oems_question7 
    WHERE  id between 1 and 40
)
UPDATE UpdateCTE   
SET q_id = SUBSTRING (@q_id ,0,CHARINDEX('_', @q_id,5) + 1 ) + ' ' + CONVERT(NVARCHAR,RowNum)


end