在sql中将varchar meridienm时间改为24小时

我已经写了这个测试-看起来很有效。与午夜一起工作并添加前导零。

更新:

DROP TABLE #times

CREATE TABLE #times
(
    TimeOfDay  VARCHAR(32),
    TimeMeridiem VARCHAR(32),
    TwentyFourHourTime VARCHAR(32)
)

INSERT INTO #times (TimeOfDay, TimeMeridiem) VALUES ('1:00', 'PM')
INSERT INTO #times (TimeOfDay, TimeMeridiem) VALUES ('1:00', 'AM')
INSERT INTO #times (TimeOfDay, TimeMeridiem) VALUES ('12:00', 'PM')

UPDATE #times SET TwentyFourHourTime = REPLACE(Right(Replicate('0',5) +
REPLACE((SELECT CASE WHEN TimeMeridiem = 'PM' THEN
CAST((SELECT REPLACE(TimeOfDay,':','.')) AS dec(10,2)) + 12 ELSE 
(SELECT REPLACE(TimeOfDay,':','.')) END), '24.', '00.') ,5), '.', ':')

SELECT * FROM #times

结果:

TimeOfDay TimeMeridiem TwentyFourHourTime 
--------- ------------ ------------------ 
1:00      PM           13:00              
1:00      AM           01:00              
12:00     PM           00:00  

请尝试以下查询:

update tableName set  TwentyFourHourTime =
case TimeMeridiem 
WHEN 'PM' THEN Convert(varchar,dateadd(hour,12,TimeOFDay),108)
 ELSE Convert(varchar,TimeOFDay,108)
end