MongoDB modifier (3)

1. Update

Db.persons.update ({name: "Caohui"},{id:2}); update only one, replace update directly

Db.persons.update ({name: "Caohui"},{id:2},true), update only one, replace update directly, insert if not present

2. Full-scale update

Db.persons.update ({name: "Caohui"},{$set: {id:2}},false,true); full-scale local update

3. $set {$set: {Field:value}}

It is used to specify a key value pair, if there is a key value is modified, does not exist to add

4. $inc {$inc: {Field:value}}

Only used with numeric types, you can add and subtract numeric types that correspond to the specified key

5. $unset {$unset: {field:1}} to delete the corresponding key value

6. $push {$push: {Field:value}}

Add data to the array, or create if the key does not exist

7. $pushAll {$push: {Field:[value]}}

Adding elements to an array in bulk

8. $addToSet {$addToSet: {Field:value}}

Add elements to the array, if present, without adding

9. $pop {$pop: {Field:value}}

Delete data to an array, 1 delete the last value;-1 Delete the first value

Ten. $pull {$pull: {Field:value}}

Deletes the value specified by the array

$pullAll {$pullAll: {Field:value}}

To delete multiple corresponding array values

12. Array Locator $

Db.books.update ({"Boook.type": "JS"},{$set: {"Boook.$.count": 222}})

MongoDB modifier (3)