MongoDB Learning Notes < two >

Continue with the shell of the study, and continue to learn the following knowledge:

--Document data insertion

--Document Data deletion

--Document Data Update

Specific as follows:

1. Inserting a document

Db.person.insert ({"Name": "Xiaoming"})

2. BULK INSERT

Use the For loop to do this, such as:

for (Var i=0;i<10;i++){

Db.person.insert ({"Name": i})

}

3.save operation

Similar to the insert operation, the Save action differs from the insert operation in that the insert operation will error if "_id" is encountered, and the Save action will be updated

4. Delete all data in the collection

Db.person.remove (), the collection itself and the index are not deleted.

5. Delete by condition

Db.person.remove ({"Name": "Xiaoming"})

6. Tips

If you want to delete a collection that clears a very large amount of data, deleting the collection directly and re-indexing is much more efficient than using the Remove method directly.

7. Document Update operations

Db. Document name. Update ({finder},{modifier})

For example: Db.person.update ({"Name": "Xiaoming"},{$set: {"name": "Xiaohong"}})

8.insertOrUpdate operation

Db. Document name. Update ({finder},{modifier},true)

If the query detects the document, it is updated, and if it is not found, the insert operation

9. Batch update operations

if it is: db. The document name. Update ({query},{modifier}) modifies only the first document to which the update query is made, not all updates

So, take the following approach: DB. Document name. Update ({finder},{modifier},false,true)

MongoDB Learning Notes < two >