Question

I have created a join for an application I am working on.

SELECT community.id, 
       community.name, 
       property.type, 
       property.lowest_price, 
       property.highest_price,
       property.commission_rate,
       property.fixed_bonus 
  FROM community, 
       property 
 WHERE community.zip IN ($zips) 
   AND property.community_id = community.id

I am looking to select an additional value that requires following three relations and am unsure the best way to do that.

The value I want to get is builder_group.name

The community table has community.user_id which correlates with the builder table builder.user_id

The builder table also has a builder.builder_group_id which correlates with the builder_group table’s builder_group.id

The builder_group table finally has the value I want to select builder_group.name

Also, what is the best way to return the count for pagination purposes. Is it best to just do it once initially without returning columns and pass along at the PHP level or can it be returned with the SELECT without significant overhead?

Answer 1

If you switch to explicit JOIN conditions, things become clearer:

SELECT community.id, community.name,
       property.type, property.lowest_price, property.highest_price, property.commission_rate, property.fixed_bonus,
       builder_group.name
FROM community
JOIN property      on property.community_id = community.id
JOIN builder       on builder.user_id = community.user_id
JOIN builder_group on builder_group.id = builder.builder_group_id
WHERE community.zip IN ($zips)

If you’re worried about all those JOINs being slow then review the indexes on the columns involved in the join conditions (yet another reason to use explicit JOINs) and profile the query.

As far as your pagination question goes, You might want to read about the FOUND_ROWS() function.