Update Operators of MongoDB
Update Operators are very useful while modifying the collections means while using db.collection.update(),
db.collection.findAndModify().
The general way of usage of update operators are in this way
{
$operator: {<field1>:<value1>,<field2>:<value2>,…},
$operator: {<field1>:<value1>,<field2>:<value2>,…}
}
Some Key Update Operators
| Name | Description |
|---|---|
| $inc | Increments the value of the field by the specified amount. |
| $mul | Multiplies the value of the field by the specified amount. |
| $rename | Renames a field. |
| $setOnInsert | Sets the value of a field if an update results in an insert of a document. Has no effect on update operations that modify existing documents. |
| $set | Sets the value of a field in a document. |
| $unset | Removes the specified field from a document. |
| $min | Only updates the field if the specified value is less than the existing field value. |
| $max | Only updates the field if the specified value is greater than the existing field value. |
| $currentDate | Sets the value of a field to current date, either as a Date or a Timestamp. |