sql - SELECT CASE 语法错误

Question

我有以下@temp 表：

------------------------------------
|Condition_ID   Operator   Order    |
|     1            ==        1      |
|     2            <>        3      |
|     3            ==        2      |
------------------------------------

我想实现一个 SELECT CASE，它将根据 Operator 输出特定消息

然而，这给我一个Incorrect syntax near the keyword 'PRINT'.错误。

SELECT CASE
    WHEN Operator LIKE '=='
        THEN PRINT 'EQUALS'
    WHEN Operator LIKE '<>'
        THEN PRINT 'NOT EQUALS'
END AS Operator
FROM @temp

我究竟做错了什么？

Answer 1

你不能混合PRINT和SELECT

SELECT CASE WHEN Operator LIKE '=='
            THEN 'EQUALS'
            WHEN Operator LIKE '<>'
            THEN 'NOT EQUALS'
       END AS Operator
FROM @temp

Answer 2

你只需要删除PRINT

SELECT CASE
    WHEN Operator LIKE '=='
        THEN 'EQUALS'
    WHEN Operator LIKE '<>'
        THEN 'NOT EQUALS'
END AS Operator
FROM @temp

您不能在 a 中使用 a PRINT，SELECT也不需要 -SELECT将为您检索适当的值。

Answer 3

这工作::

   SELECT CASE
    WHEN opr LIKE '=='
        THEN 'EQUALS'
    WHEN opr LIKE '<>'
        then 'NOT EQUALS'
    else
        'wrong i/p'
    end
as operator
FROM tbl1;

Answer 4

试试这个，没有打印选项

SELECT CASE 
        WHEN Operator LIKE '=='
        THEN 'EQUALS'
        WHEN Operator LIKE '<>'
        THEN 'NOT EQUALS'
   END AS Operator
   FROM @temp