MSSQL changing a return value only if it pass a Boolean_expression

i want to do something like this

SELECT (开发者_如何学运维if T.EndTime = '00:00:00' THEN '23:59:59' ELSE T.EndTime) AS EndTime from Table AS T

i know the solution should be simple but i just cant find away to make it work

You want a CASE:

http://msdn.microsoft.com/en-us/library/ms181765.aspx

SELECT
   CASE T.EndTime
      WHEN '00:00:00' THEN '23:59:59'
      ELSE T.EndTime
   END
FROM ...

CASE is what you are looking for:

SELECT (CASE WHEN T.EndTime = '00:00:00' 
             THEN '23:59:59' 
             ELSE T.EndTime END) AS EndTime 
from Table AS T

SELECT 
      CASE EndTime
         WHEN '00:00:00' THEN '23:59:59'
         ELSE EndTime
      END

If the column T.EndTime is of data type DateTime, you might want to convert the value to string first. So, the query would be something like this. Value 8 used in Convert function returns datetime in the format hh:mi:ss. You can find the list of formats for Cast or Convert at MSDN website.

SELECT  CASE 
            WHEN CONVERT(VARCHAR, T.EndTime, 8) = '00:00:00' THEN '23:59:59'
            ELSE T.EndTime
        END
FROM    dbo.TableData T