MySQL: Query and join two tables

Question

I have two tables that I believe I want to JOIN. I\'m very new to this and am not completely sure…

The first table is called venues with the variables <

Answer 1

You want to find venues that match conditions in two rows in table venue_terms. This can be accomplished by various methods. The most usual is by joining that table twice (another would be by a grouping query).

Here's the first way. Join twice to the venue_terms table:

SELECT v.id                                  --- whatever columns you need 
     , v.slug                                --- from the venues table
     , v.name
FROM venues AS v
  INNER JOIN venue_terms AS vt1
    ON  vt1.venue = v.id
  INNER JOIN venue_terms AS vt2
    ON  vt2.venue = v.id
WHERE ( vt1.option = 1 AND vt1.value = 10 )
  AND ( vt2.option = 2 AND vt2.value = 4 ) ;

If you have 3 conditions, join thrice. If you have 10 conditions, join 10 times. It would be good for the efficiency of the query to have a compound index on (option, value, venue) in the terms table.