Question

I have two tables

table COMMUNITY
  id, 
  name, 
  etc.

table PROPERTY
  id,
  community_id,
  type,
  price,
  rate,
  etc.

There are four possible property types and a community can have info for one or more of the different types.

I am trying to figure out how to combine the information for each community into one row.
For instance I might want to get a row which includes

community.id, community.name, condo.price, condo.rate, town_home.price, town_home.rate

Of course there aren’t tables for condo or town_home, the property type is represented in the property table by a column and a community can have multiple property rows.

My first thought was to use multiple joins on the table with aliases, but I can’t seem to get anything that works properly.

Any suggestions?

Answer 1

You can use left join for this.

SELECT c.id, c.name, condo.price, condo.rate, town_home.price, town_home.rate
FROM Community c
LEFT JOIN Property condo ON condo.community_id = c.id AND condo.type = 'condo'
LEFT JOIN Property town_home ON town_home.community_id = c.id AND town_home.type = 'town_home'