Database
[{"id":"613bd938774f3b0fa8f9c1ce","address":"1","contracts":[{"id":"5a934e000102030405000000"},{"id":"5a934e000102030405000001"},{"id":"5a934e000102030405000002"}]},{"id":"613bd938774f3b0fa8f9c1cf","address":"2","contracts":[{"id":"5a934e000102030405000000"},{"id":"5a934e000102030405000001"},{"id":"5a934e000102030405000002"}]}]
Query
db.collection.update({"id":"613bd938774f3b0fa8f9c1ce"},{"$pull":{"contracts":{"id":"5a934e000102030405000001"}}})