rethinkdb check if record exists

问题

Here is an example:

r.db('my_db').table('my_table').get('my_record_id_123')

The above code works fine, but returns the record. The records in this table are huge. Is there a way to check if the record with that specific id exists or not without returning the record itself?

回答1:

Perhaps this is what you want (it will return true if the record exists or false otherwise):

r.db('my_db')
  .table('my_table')
  .getAll('my_record_id_123')
  .count()
  .eq(1)

回答2:

returns number

r.db('my_db')
  .table('my_table')
  .count(function(user){
    return user('id').eq(1121)
  })

回答3:

r.db('my_db')
  .table('my_table')
  .getAll('my_record_id_123')
  .contains()

This works for me :)

来源：https://stackoverflow.com/questions/43782915/rethinkdb-check-if-record-exists