Using same column multiple times in WHERE clause

Question

I have a following table structure.

USERS

PROPERTY_VALUE

PROPERTY_NAME

USER_

Answer 1

SELECT * FROM users u
INNER JOIN user_property_map upm ON u.id = upm.user_id
INNER JOIN property_value pv ON upm.property_value_id = pv.id
INNER JOIN property_name pn ON pv.property_name_id = pn.id
WHERE (pn.id = 1 AND pv.id IN (SELECT id FROM property_value WHERE value 
like '101') )
OR ( pn.id = 2 AND pv.id IN (SELECT id FROM property_value WHERE value like 
'102'))

OR (...)
OR (...)

You can't do AND because there is no such a case where id is 1 and 2 for the SAME ROW, you specify the where condition for each row!

If you run a simple test, like

SELECT * FROM users where id=1 and id=2 

you will get 0 results. To achieve that use

 id in (1,2) 

or

 id=1 or id=2

That query can be optimised more but this is a good start I hope.