Where-clause in sql-resolver

I want to integrate an sql-db for authentication, but I cannot find, how the where-clause has to be defined.
if I input it like this

ID_Mandant = 5

the test shows every user from the table. If I input it without the spaces I get:

failed to retrieve users: not enough values to unpack (expected 3, got 1)

There’s no hint in the manual…

Thanks for your help

Looking at the code it seems like you need to enter

ID_Mandant == 5

Thats the trick, thank you!!