CODEWITHSUNDEEP
ruby-on-railsrubyactiverecordruby-on-rails-4
user1678808
user1678808

Reputation:

How to limit a model to create one record per day?

Business logic: A user can only create one entry for a journal per day. Before an entry can be created, it must query the records to determine if an entry has already been created for today.

I was looking for advice on the best way to approach this. I had a few ideas how to implement it on the client-side, but I'd really like to have validation on the model layer instead. Any help would be appreciated.

Upvotes: 6

Views: 1885

Answers (1)

Kombajn zbożowy
Kombajn zbożowy

Reputation: 10693

Create a unique index on the journal table:

add_index :journal_entries, [:user_id, :created_on], unique: true

Then only one record with given user_id and date can be created and the database will raise an exception if this is violated. Note that created_on must be a date column, not datetime.

This is the only way to make it 100% sure that you don't get duplicates without explicit exclusive lock on the table.

Upvotes: 7

Related Questions