Unfortunately, I can't figure out how to turn the _id ObjectID, into a _id with a unique number generated by a number.

For example: Right now the generation is like this

[
{
 _id: 'adioj2ouro21jr9o3',
 // ...
}
]

And we need to

[
{
 id: 1,
 // ...
}
]

CodePudding user response：

https://www.mongodb.com/basics/mongodb-auto-increment

I have not used mongoDB myself. It appears that mongoDB doesnt support auto increment like MySQL would.

Could you use javascript to add N 1 on the last id in the table and manually create the ID field as needed?

CodePudding user response：

1. The build-in mechanism in mongoDB to auto generate ObjectId() is a very good and easy way to have unique _id and also contain the insertion date which sometimes make troubleshooting easier.

2. You cannot replace having default _id key with id , but you can have both _id and id ...

3. However you can insert different document in _id instead of the default ObjectId().

4. if you want the _id to be number you can read max(_id) and insert new document with inc(max(_id)) but this is not scalalble solution since if your writes increase it can become a bottleneck at some point.

Finally it is recomended to leave the default ObjectId() as your auto generated _id ...