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Update Operators
The following modifiers are available for use in update operations;
e.g. in db.collection.update()
and
db.collection.findAndModify()
.
Update Operators
Fields
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. |
Array
Operators
Name |
Description |
$ |
Acts as a placeholder to update the first element that matches the query condition in an update. |
$addToSet |
Adds elements to an array only if they do not already exist in the set. |
$pop |
Removes the first or last item of an array. |
$pullAll |
Removes all matching values from an array. |
$pull |
Removes all array elements that match a specified query. |
$pushAll |
Deprecated. Adds several items to an array. |
$push |
Adds an item to an array. |
Modifiers
Name |
Description |
$each |
Modifies the $push and $addToSet operators to append multiple items for array updates. |
$slice |
Modifies the $push operator to limit the size of updated arrays. |
$sort |
Modifies the $push operator to reorder documents stored in an array. |
$position |
Modifies the $push operator to specify the position in the array to add elements. |
Bitwise
Name |
Description |
$bit |
Performs bitwise AND , OR , and XOR updates of integer values. |
Isolation
Name |
Description |
$isolated |
Modifies the behavior of a write operation to increase the isolation of the operation. |