mysql - Query not working when looking for null values on the where clause -


i got query works perfectly:

select folder.folderid, folder.foldername folder inner join collaborators on collaborators.folderid = folder.folderid collaborators.userid = 23

but when added on clause: "and folder.parent = null" doesnt work. complete query is:

select folder.folderid, folder.foldername folder inner join collaborators on collaborators.folderid = folder.folderid collaborators.userid = 23 , folder.parent = null

does know whats going on? thanks

when dealing null, cannot use = or <> since values unknown instead use is null or is not null,

where collaborators.userid = 23 , folder.parent null

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