SQL Server CASE .. WHEN .. IN statement

问题:

On SQL server 2005 I am trying to query this select statement

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 

It returns the error below

Msg 156, Level 15, State 1, Line 4 Incorrect syntax near the keyword 'IN'.

Please give me some advice on what could be wrong with my code.

回答1:

CASE AlarmEventTransactions.DeviceID should just be CASE.

You are mixing the 2 forms of the CASE expression.

回答2:

Thanks for the Answer I have modified the statements to look like below

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

回答3:

Try this...

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

Just remove highlighted string

SELECT AlarmEventTransactionTableTable.TxnID, CASE AlarmEventTransactions.DeviceID WHEN DeviceID IN('7', '10', '62', '58', '60', ...)

回答4:

It might be easier to read when written out in longhand using the 'simple case' e.g.

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

...which kind makes me thing that perhaps you could benefit from a lookup table to which you can JOIN to eliminate the CASE expression entirely.