>>If you want to make sure that all records are enabled, then
>>

>>select M.Numero
>>from Master M inner join ManyToManyTable MM on M.Numero = MM.NoMaster
>>inner join ChildTable C on MM.NoChildTable = C.Numero
>>group by M.Numero
>>having min(case when C.Enabled = 1 then 1 else 0 end) = 1 -- means all records are enabled
>>and sum(case when C.Enabled = 1 then 1 else 0 end) = count(C.Numero) -- total number of enabled records = total number of joined records

>
>Unfortunately, this does not work either.

What exactly is the requirement here? Can you post some input and a bit of output?

Do you want to only get Master.Numero if all Child records for that Numero (through ManyToManyTable) are Enabled?