Selecting values depending on two tables

[Ob_server_]

I have a serious problem, and I don't know if it's even to in MySQL (my mind is friend and I don't understand heck anymore 🙂). Anyway, here is my problem;
I want to select rows from table proto_join if the value in the column MH_one also exists in table uni_join column buildingid, and if the value in column MH_one also exists in table uni_join, colum buildingid. I forged the query:
SELECT * FROM proto_join WHERE 'proto_join.MH_one' = 'uni_join.buildingid' AND 'proto_join.MH_two' = 'uni_join.buildingid'

But this attempt failed miserably. I hope someone can help me out 😕 .

[leatherback]

Hi, perhaps lose the single quotes around the tables and colum names. Perhaps you need to add brackets arount the statements:

SELECT * FROM proto_join WHERE (proto_join.MH_one = uni_join.buildingid) AND (proto_join.MH_two = uni_join.buildingid)

Hope this helkps.

J.