Re: Poor Query

> Just One, user can i have only one bankaccount.

Ah well, in that case :
This is your query :

select userID, fname, lname, email, phone, dateEntered, dateCanceled,
dateSuspended, billAmount, billDate, dateBilled, datePaid, '?' as searches
from Users u
where 1=1 AND exists (select userID
from bankaccount ba
where ba.bankaccountID = u.bankaccountID
and ba.accountnumber = '12345678')
AND exists (select userID
from bankaccount ba
where ba.bankaccountID = u.bankaccountID
and ba.routingNumber = '12345678')
order by UserID desc
limit 500

What it does is scan all users, and for each user, test if it has the
accountnumber or the routingNumber you seek. You're reversing the problem
: you should first look for accountnumber and routingNumber, THEN look for
the user :

SELECT * FROM Users WHERE bankaccountID IN
(SELECT bankaccountID FROM bankaccount WHERE accountnumber = '12345678'
OR/AND routingNumber = '12345678')

or :

SELECT * FROM Users WHERE userID IN
(SELECT userID FROM bankaccount WHERE accountnumber = '12345678' OR/AND
routingNumber = '12345678')

There is something very strange in your query, it seems that bankaccount
and Users both have a UserID column and a bankaccountID column. Is this
normal ? It looks denormalized to me...