Question

I am running following query..

Select T1.* from T1 
LEFT JOIN T2 ON T1.C1 = T2.C1 
LEFT JOIN T3 ON T2.C3 = T3.C3
ORDER BY Case When T1.C1 = 'ABC' THEN 'XYZ' END  AS COMMENTS  

Its giving me Syntax error near AS. Unable to figure out the error.

Answer 1

It’s because you are trying to assign an alias to the ORDER BY clause – this is not allowed and I’m not sure what you want to achieve here?

You either need:

Select T1.* from T1 
LEFT JOIN T2 ON T1.C1 = T2.C1 
LEFT JOIN T3 ON T2.C3 = T3.C3
ORDER BY Case When T1.C1 = 'ABC' THEN 'XYZ' END

Or, if you want that CASE value to be returned in the SELECT as well, then you need:

Select T1.*, Case When T1.C1 = 'ABC' THEN 'XYZ' END AS COMMENTS
from T1 
    LEFT JOIN T2 ON T1.C1 = T2.C1 
    LEFT JOIN T3 ON T2.C3 = T3.C3
ORDER BY Case When T1.C1 = 'ABC' THEN 'XYZ' END

Also, again not sure of intention here so it depends, but you may need an ELSE on that CASE…
e.g.

ORDER BY CASE WHEN T1.C1 = 'ABC' THEN 'XYZ' ELSE T1.C1 END