MongoDB Updates Update

1. $inc

Usage: {$inc: {Field:value}}

Function: Adds value to a field of a number

> db.test1.update ({' name ': ' Wang '},{$inc: {age:1}})

> db.test1.find ({' name ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "name": "Wang", "age": +, "sex": "M"}

2. $set

Usage: {$set: {Field:value}}

Function: Sets the value of a field in a document

> db.test1.update ({' name ': ' Wang '},{$set: {' sex ': ' F '}})

> db.test1.find ({' name ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "name": "Wang", "age": +, "sex": "F"}

3. $unset

Usage: {$unset: {field:1}}

Role: Delete a field

> db.test1.update ({' name ': ' Wang '},{$unset: {' Sex ': 1}})

> db.test1.find ({' name ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "age": +, "name": "Wang"}

4. $push

Usage: {$push: {Field:value}}

Function: Append value to field. Note: field can only be an array type, and if field does not exist, an array type is automatically inserted

> db.test1.update ({' name ': ' Wang '},{$push: {' sex ': ' F '}})

> db.test1.update ({' name ': ' Wang '},{$push: {' sex ': ' M '}})

> db.test1.find ({' name ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "age": +, "name": "Wang", "Sex": ["F", "M"]}

5.pushAll

Usage: {$pushAll: {Field:value_array}}

Function: Use the same as $push, except that $pushall can append multiple values to an array field at a time.

> db.test1.update ({' name ': ' Wang '},{$pushAll: {' sex ': [' m or f ', ' M and F '}})

> db.test1.find ({' name ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "age": +, "name": "Wang", "Sex": ["F", "M", "M or F", "M and F"] }

> db.test1.update ({' name ': ' Wang '},{$push: {' sex ': [' m or f ', ' M and F '}})

> db.test1.find ({' name ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "age": +, "name": "Wang", "Sex": ["F", "M", "M or F", "M and F", ["M or F", "M and F"]] }

6. $addToSet

Usage: {$addToSet: {Field:value}}

Function: Adds a value to the array, and only increases if the value does not exist in the array.

> db.test1.update ({' name ': ' Wang '},{$addToSet: {' sex ': [' M or F ', ' MF ']}})

> db.test1.find ({' name ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "age": +, "name": "Wang", "Sex": [ "F", "M", "M or F", "M and F", [ "M or F", "M and F"], [ "M or F", "MF"]}

7. $pop

Usage: Delete the first value in the array: {$pop: {field:-1}}, delete the last value in the array: {$pop: {field:1}}

Function: Used to delete a value within an array

> db.test1.find ({' name ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "age": +, "name": "Wang", "Sex": ["F", "M", "M or F", "M and F"] }

> db.test1.update ({' name ': ' Wang '},{$pop: {' Sex ': 1}})

> db.test1.find ({' name ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "age": +, "name": "Wang", "Sex": ["F", "M", "M or F"]}

8. $pull

Usage: {$pull: {Field:_value}}

Function: Removes a value equal to _value from the array field

> db.test1.update ({' name ': ' Wang '},{$pull: {' sex ': ' F '}})

> db.test1.find ({' name ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "age": +, "name": "Wang", "Sex": ["M", "M or F"]}

Ten. $rename

Usage: {$rename: {old_field_name:new_field_name}}

Role: Renaming a field

> db.test1.update ({' name ': ' Wang '},{$rename: {' name ': ' Names '}})

> db.test1.find ({' name ': ' Wang '})

> db.test1.find ({' names ': ' Wang '})

{"_id": ObjectId ("58662477fb6a734e8f45133f"), "age": +, "names": "Wang", "Sex": ["M", "M or F"]}

MongoDB Updates Update