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Mongo Non-Primary Key objectid Can Be Empty

 May 12, 2019   mongodb, question

2.

user:{
 father:objectid,
 }

What if the foreign key is empty, only string can be stored?

If you do not set the Objectid of mongodb, the system will automatically generate it.

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<< Mongodb: Why can’t you set a unique value like this? MONGODB failed to start >>

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