How to change a value name during output

I am trying to change the name of a stored value when I execute my SQL script:

SELECT
    PERSONNUM, 
    PAYCODENAME, 
    CAST(WFCTIMEINSECONDS AS FLOAT)/3600 AS Total_Hours
FROM
    VP_ALLTOTA开发者_StackOverflowLS
WHERE
    Applydate >= '09/25/2011' AND
    Applydate <= '10/01/2011' AND
    PAYCODENAME IN ('Vacation'
                    ,'Sick Leave - Paid'
                    ,'Personal Business - Paid'
                    ,'Comp Time - Paid'
                     )

I want the Vacation to be VAC, Sick Leave - Paid to be SIC, Personal Business - Paid to be PER and

The easiest way is a list of CASE options for substitutions.

SELECT PERSONNUM
       PAYCODENAME CASE WHEN 'Vacation' THEN 'VAC'
                        WHEN 'Sick Leave - Paid' THEN 'SIC'
                        WHEN 'Personal Business - Paid' THEN 'PER'
                        ELSE PAYCODENAME END AS PAYCODENAME
       ....

Use a CASE statement:

SELECT
    PERSONNUM, 
    CASE PAYCODENAME
    WHEN 'VACATION' THEN 'Vac'
    WHEN 'Sick Leave - Paid' THEN 'SIC'
    WHEN 'Comp Time - Paid' THEN 'PER'
    ELSE PAYCODENAME
    END,
    cast(WFCTIMEINSECONDS as float)/3600 as Total_Hours
FROM
    VP_ALLTOTALS
WHERE
    Applydate >= '09/25/2011' AND
    Applydate <= '10/01/2011' AND
    PAYCODENAME in ('Vacation'
    ,Sick Leave - Paid'
    ,'Personal Business - Paid'
    ,'Comp Time - Paid'
    )

You can use a permanent table, derived table, or common table expression (subject to availability in your RDBMS) with the mappings and join onto that in place of the in list.

WITH PAYCODES(PAYCODENAME, LABEL)
     AS (SELECT 'Vacation',
                'VAC'
         UNION ALL
         SELECT 'Sick Leave - Paid',
                'SIC'
         UNION ALL
         SELECT 'Personal Business - Paid',
                'PER'
         UNION ALL
         SELECT 'Comp Time - Paid',
                '')
SELECT PERSONNUM,
       LABEL AS PAYCODENAME,
       CAST(WFCTIMEINSECONDS AS FLOAT) / 3600 AS Total_Hours
FROM   VP_ALLTOTALS
       JOIN PAYCODES
         ON PAYCODES.PAYCODENAME = VP_ALLTOTALS.PAYCODENAME
WHERE  Applydate >= '09/25/2011'
       AND Applydate <= '10/01/2011'