Why is my left join not returning nulls?

Question

In sql server 2008, I have the following query:

select      
    c.title as categorytitle,
    s.title as subcategorytitle,
    i.title as itemtitle
from cat         


        

Answer 1

Your "WHERE" criteria on i.siteid means that there has to be an "items" row in the output. you need to write (i.siteid is null or i.siteid = 132) or put the "i.siteid = 132" into the "ON" clause- something that will work for the itemcategories join too:

select      
    c.title as categorytitle,
    s.title as subcategorytitle,
    i.title as itemtitle
from categories c
join subcategories s on c.categoryid = s.categoryid
left join itemcategories ic on s.subcategoryid = ic.subcategoryid and ic.isactive = 1
left join items i on ic.itemid = i.itemid and i.siteid = 132
order by c.title, s.title