Question

我有一个MySQL查询，它工作正常，然后尝试在SQL Server中执行相同的查询但显示错误。

查询是：

SELECT 
    system, tst_env_name 
FROM 
   (SELECT 
       system,tst_env_name, 
       CASE 
          WHEN start_hrs < end_hrs 
            THEN (start_hrs * 60 + start_mins) < 1153 AND 1153 < (end_hrs * 60 + end_mins) 
            ELSE ((start_hrs * 60 + start_mins) < 1153 AND 1153 < 1439) 
                 OR (0 < 1153 AND 1153 < (end_hrs * 60 + end_mins)) 
        END co 
     FROM tst_env_details 
     WHERE project = 'JupitorQA') sub 
WHERE 
    sub.co=0 
    AND system IN ('0', '0.0.0.581');

错误是

“＆lt;”附近的语法不正确 'co'
附近的语法不正确

我上面的查询做错了什么？

Answer 1

你可以像这样使用，我将cons_or start_hr作为字符串，你可以像datatype一样添加SomeValue

SELECT system,tst_env_name 
  FROM (SELECT 
             system,tst_env_name, 
             CASE WHEN 
                  start_hr ='SomeValue' 
             END CASE)

Answer 2

你不能在select子句中写出直接条件（在使用case之后），而不是像下面那样：

SELECT   stock.name,
      CASE 
         WHEN stock.quantity <20 THEN 'Buy urgent'
         ELSE 'There is enough'
      END
FROM stock

这样会导致错误

select 1 = 1

错误消息：

Msg 102，Level 15，State 1，Line 1

'='附近的语法不正确。

Answer 3

我假设您打算将它们视为布尔表达式，在false时评估为0.

SELECT 
    system, tst_env_name 
FROM 
   (SELECT 
       system,tst_env_name, 
       CASE 
          WHEN start_hrs < end_hrs 
            /* I stripped out the unnecessary comparisons */
            THEN CASE WHEN (start_hrs * 60 + start_mins) < 1153 AND 1153 < (end_hrs * 60 + end_mins) THEN 1 ELSE 0 END
            ELSE CASE WHEN ((start_hrs * 60 + start_mins) < 1153) OR (1153 < (end_hrs * 60 + end_mins)) THEN 1 ELSE 0 END
        END co 
     FROM tst_env_details 
     WHERE project = 'JupitorQA') sub 
WHERE 
    sub.co=0 
    AND system IN ('0', '0.0.0.581');

查询CASE条件抛出错误

3 个答案: