CODEWITHSUNDEEP
ruby-on-railsactiverecord
Markus
Markus

Reputation: 4038

How to implement a unique index on two columns in rails

I have a table and I'm trying to add a unique index on two columns. Those columns are also indexed. So my question is if I just can remove the indexes who were just for one column or if I have to use all three indexes:

add_index "subscriptions", ["user_id"]
add_index "subscriptions", ["content_id"]
add_index "subscriptions", ["user_id"], ["content_id"], :unique => true

Upvotes: 123

Views: 54358

Answers (1)

shingara
shingara

Reputation: 46914

add_index :subscriptions, [:user_id, :content_id], unique: true

Upvotes: 242

Related Questions