SQL Server CASE .. WHEN .. IN语句

Question

在SQL Server 2005上,我试图查询此select语句

SELECT AlarmEventTransactionTableTable.TxnID,
       CASE AlarmEventTransactions.DeviceID
         WHEN DeviceID IN( '7', '10', '62', '58',
                           '60', '46', '48', '50',
                           '137', '139', '142', '143', '164' )
           THEN '01'
         WHEN DeviceID IN( '8', '9', '63', '59',
                           '61', '47', '49', '51',
                           '138', '140', '141', '144', '165' )
           THEN '02'
         ELSE 'NA'
       END AS clocking,
       AlarmEventTransactionTable.DateTimeOfTxn
FROM   multiMAXTxn.dbo.AlarmEventTransactionTable 

它返回以下错误

消息156,级别15,状态1,行4关键字"IN"附近的语法不正确.

请给我一些关于我的代码可能出错的建议.

Answer 1

CASE AlarmEventTransactions.DeviceID应该只是CASE.

您正在混合表达式的两种形式CASE.

Answer 2

谢谢你的答案我修改了语句如下所示

SELECT
     AlarmEventTransactionTable.TxnID,
     CASE 
    WHEN DeviceID IN('7', '10', '62', '58', '60',
            '46', '48', '50', '137', '139',
             '141', '145', '164') THEN '01'
    WHEN DeviceID IN('8', '9', '63', '59', '61',
            '47', '49', '51', '138', '140',
            '142', '146', '165') THEN '02'
             ELSE 'NA' END AS clocking,
     AlarmEventTransactionTable.DateTimeOfTxn
FROM
     multiMAXTxn.dbo.AlarmEventTransactionTable

Answer 3

尝试这个...

SELECT
    AlarmEventTransactionTableTable.TxnID,
    CASE
        WHEN DeviceID IN('7', '10', '62', '58', '60',
                 '46', '48', '50', '137', '139',
                 '142', '143', '164') THEN '01'
        WHEN DeviceID IN('8', '9', '63', '59', '61',
                 '47', '49', '51', '138', '140',
                 '141', '144', '165') THEN '02'
        ELSE 'NA' END AS clocking,
    AlarmEventTransactionTable.DateTimeOfTxn
 FROM
    multiMAXTxn.dbo.AlarmEventTransactionTable

只需删除突出显示的字符串

当DeviceID IN（'7'，'10'，'62'，'58'，'60'，...）时，选择AlarmEventTransactionTableTable.TxnID，CASE AlarmEventTransactions.DeviceID

Answer 4

使用“简单情况”手写写出可能会更容易阅读，例如

CASE DeviceID 
   WHEN '7  ' THEN '01'
   WHEN '10 ' THEN '01'
   WHEN '62 ' THEN '01'
   WHEN '58 ' THEN '01'
   WHEN '60 ' THEN '01'
   WHEN '46 ' THEN '01'
   WHEN '48 ' THEN '01'
   WHEN '50 ' THEN '01'
   WHEN '137' THEN '01'
   WHEN '139' THEN '01'
   WHEN '142' THEN '01'
   WHEN '143' THEN '01'
   WHEN '164' THEN '01'
   WHEN '8  ' THEN '02'
   WHEN '9  ' THEN '02'
   WHEN '63 ' THEN '02'
   WHEN '59 ' THEN '02'
   WHEN '61 ' THEN '02'
   WHEN '47 ' THEN '02'
   WHEN '49 ' THEN '02'
   WHEN '51 ' THEN '02'
   WHEN '138' THEN '02'
   WHEN '140' THEN '02'
   WHEN '141' THEN '02'
   WHEN '144' THEN '02'
   WHEN '165' THEN '02'
   ELSE 'NA' 
END AS clocking

...这让我觉得也许你可以从查找表中受益，你可以完全JOIN消除CASE表达式。