Sha256: 7e488ace6a47d9ae28d00eb6278673b55a79ae1b868cb0eca116b437025a8470
Contents?: true
Size: 1.31 KB
Versions: 16
Compression:
Stored size: 1.31 KB
Contents
class AddDeletedAtToPatientBookmarks < ActiveRecord::Migration[4.2]
def up
add_column :patient_bookmarks, :deleted_at, :datetime
remove_index(:patient_bookmarks, [:patient_id, :user_id])
add_index :patient_bookmarks, :patient_id
# We'd like to have a unique index on [patient, user, deleted_at]
# so that there can only ever be one un-deleted (deleted_at == NULL)
# patient+user combination - ie you can't bookmark a patient twice.
# However we also want to allow historical duplicates - there can be
# many of the same patient+user combination as long as they have a different
# deleted_at datetime. Because NULLs don't help in the index for our un-deleted
# scenario (deleted_at == NULL) we have to coalesce those NULLs into the same
# valid date. This lets us have a unique index when deleted_at is NULL.
ActiveRecord::Base.connection.execute(
"CREATE UNIQUE INDEX patient_bookmarks_uniqueness
ON patient_bookmarks
(patient_id, user_id, COALESCE(deleted_at, '1970-01-01'));"
)
end
def down
remove_index(:patient_bookmarks, name: :patient_bookmarks_uniqueness)
remove_column :patient_bookmarks, :deleted_at, :datetime
add_index(:patient_bookmarks, [:patient_id, :user_id], unique: true)
remove_index :patient_bookmarks, :patient_id
end
end
Version data entries
16 entries across 16 versions & 1 rubygems