Question

This is a postgres db. I am attempting to pull dog breed names (Cane Corso, Labrador, etc) from a breed table, to display based on the foreign keys located in an animal table. My issue is the animal table has two foreign keys to this single breed table, and I keep getting errors with my query. The first breed name will return based on a left join, but the second I cannot get the name to display as I already have a left join. Below is a simplified outline of what I am attempting to do:

breed table (ID, BreedName)
animal table (ID, breedID, breed2ID)

SELECT animal.ID, breed.BreedName FROM animal LEFT JOIN breed ON animal.breedID=breed.ID WHERE animal.ID='7';

What I need to do is also get the BreedName to join for animal.breed2ID which I am failing miserably at. I could easily hard code the breed names and have it display in the application, but this is not conducive to changes, additions, or deletions of breed names in the database.

Answer 1

just do another join on that same table:

SELECT animal.ID, breed1.BreedName as BreedName1, breed2.BreadName as BreadName2 
FROM animal 
   LEFT JOIN breed as breed1 ON animal.breedID=breed1.ID 
   LEFT JOIN breed as breed2 ON animal.breedID=breed2.ID 
WHERE animal.ID='7';