>>

>>SET @SQL='...WHERE Client.City=''Michel''''s city'''

>
>Thanks, but is this syntax also supported for such situation:
>
>

>SET @SQL='...THEN Client.City ELSE '''''''' END'',''L...'
>

>
>...where the ELSE is supposed to have a result of ''.
>
>It seems the first example works. But, the script cannot be executed as it fails later on in such situation.

You need to use 4 single quotes if you want to use a string.