更改SQL查询中的返回值

Question

I am working with real time viewing program that makes SQL queries (and let me edit bit of the code)

At the moment code is:

SELECT 
    [LogonName] AS [Logon name], 
    [LogonExtension] AS [Logon extension], 
    [VoiceReady] AS [Ready for Voice], 
    [CallState] AS [Call state]
FROM 
    [AgentPerformance]
WHERE 
    (AgentID IN (1, 2, 3))

This returns:

Now my question is that is there any way to change the returned "call state" values to let's say busy, free, handling etc... (there are 3 different values).

I have tried for example:

SELECT 
    [LogonName] AS [Logon name], 
    [LogonExtension] AS [Logon extension], 
    [VoiceReady] AS [Ready for Voice], 
    [CallState] AS [Call state]
FROM
    [AgentPerformance]
WHERE 
    (AgentID IN (1, 2, 3))

SELECT 
    CASE 
       WHEN CallState = 0 THEN 'No'
       WHEN CallState = 1 THEN 'Yes
       ELSE 'Maybe'
    END AS kakaduu
FROM 
    AgentPerformance

But this didn't work for me.

Answer 1

Your CASE expression need to be in SELECT list along with another columns. second SELECT was incorrect syntax in your example.

So, try this:

SELECT [LogonName] AS [Logon name], [LogonExtension] AS [Logon extension], [VoiceReady] AS [Ready for Voice], [CallState] AS [Call state],
CASE 
    WHEN CallState = 0 then 'No'
    WHEN CallState = 1 then 'Yes'
    ELSE 'Maybe'
END
AS kakaduu
FROM [AgentPerformance]
WHERE   AgentID IN (1, 2, 3)