Question

I am using SQL Server 2005. I am trying to do a select from a TINYINT field. If the field’s value is 0 I want to select an empty string instead ‘ ‘ . The fields name is level. HEre is what I am doing:

SELECT 
[Level] = 
Case 
t.[Level]
    WHEN 0 THEN ' '
    ELSE t.[Level]
END
FROM table t 

This code always returns 0. I was trying to troubleshoot the issue and tried this:

SELECT 
[Level] = 
Case 
t.[Level]
    WHEN 0 THEN 'test'
    ELSE t.[Level]
END
FROM table t 

And I got a the error Conversion failed when converting the varchar value 'test' to data type tinyint

So I’m seeing that there is a conversion problem here. I’ve tried:

SELECT 
[Level] = 
Case 
t.[Level]
    WHEN 0 THEN CONVERT(VARCHAR,t.[level])
    ELSE t.[Level]
END
FROM table t 

But this of course still returns 0, just the character, so it’s still not doing what I need. I am thinking that there is most likely a better way to do this but am not sure how to approach it. Could anyone give me some advice on how to handle this? Thanks much!

Answer 1

For CASE statements, all returned values must be of the same type (or automatically convertable); that’s the reason why '' was working, but 'test' wasn´t.

SELECT [Level] = 
Case t.[Level]
    WHEN 0 THEN ' '
    ELSE CONVERT(VARCHAR(3), t.[Level])
END
FROM table t