Why am I getting the error "non-boolean type specified in a context where a condition is expected" for this request? I am getting this error :
"Error 102 : non-boolean type specified in a context where a condition is expected"
for this request : 

DECLARE @num_dossiers TABLE (num_dossier INT,indice NVARCHAR(3))
insert into @num_dossiers
select num_dossier,indice from dossier where num_sec=57

delete from constitue where (num_dossier,indice) in select (num_dossier,indice) from @num_dossiers  


The request triggering the error is the last one :  

delete from constitue where (num_dossier,indice) in select (num_dossier,indice) from @num_dossiers   


What could be the cause of this error ?
SQL Server doesn't support a multi-column IN clause (unlike Oracle).

delete 
from constitue 
where (num_dossier,indice) in select (num_dossier,indice) from @num_dossiers 


This can be rewritten as a EXISTS:

DELETE c
FROM constitue c
WHERE EXISTS 
    (SELECT 1 FROM @num_dossiers nd WHERE n.num_dossier = c.num_dossier AND n.indice = c.indice);