Table Join Statement Returns Repeat Rows

Hello All.

I am struggling with the below join block in my stored procedure.
I can't seem to get the duplicate row problem to go away. It seems that SQL is treating each new instance of an email address as reason to create a new row despite the UNIONs.
I understand that if I am using UNION, using DISTINCT is redundant and will not solve the duplicate row problem.

Primary Keys: none of the email address columns are primary keys. Each table has an incrementing ID column that serves
as the primary key.

I am guessing I am encountering this problem because of how
I have structured my Join statements? Is it possible to offer advice without a deeper understanding of my data model or
do you need more information?

Thanks for any tips.


Code:


select emailAddress from Users union
select user_name from PersonalPhotos union
select email_address from EditProfile union
select email_address from SavedSearches union
select distinct email_address from UserPrecedence union
select email_address from LastLogin) drv
Left Join Users tab1 on (drv.emailAddress = tab1.emailAddress)
Inner Join UserPrecedence tab5 on tab5.UserID=tab1.UserID
Left Join PersonalPhotos tab2 on (drv.emailAddress = tab2.user_name)
Left Join LastLogin tab4 on (drv.emailAddress = tab4.email_address)
Left Join EditProfile tab3 on (drv.emailAddress = tab3.email_address)
Left Join SavedSearches tab6 on (drv.emailAddress = tab6.email_address