in mongodb, there are two general way to connect with two tables. manual connection and use dbref 1. basically manual connection firstly init the data which was saved in the different collections. the result： 2 usage of dbref grammar: the
in mongodb, there are two general way to connect with two tables. manual connection and use dbref
1. basically manual connection firstly init the data which was saved in the different collections.
the result：
2 usage of dbref
grammar:
the example:
attention: the above example has some question;