【MongoDB】Update Operators

$currentDate

Sets the value of a field to current date, either as a Date or a Timestamp.

$inc

Increments the value of the field by the specified amount.

$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.

$mul

Multiplies the value of the field by the specified amount.

$rename

Renames a field.

$set

Sets the value of a field in a document.

$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.

$unset

Removes the specified field from a document.

$

Acts as a placeholder to update the first element that matches the query condition.

$[]

Acts as a placeholder to update all elements in an array for the documents that match the query condition.

$[<identifier>]

Acts as a placeholder to update all elements that match the arrayFilters condition for the documents that match the query condition.

$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.

$pull

Removes all array elements that match a specified query.

$push

Adds an item to an array.

$pullAll

Removes all matching values from an array.

$each

Modifies the $push and $addToSet operators to append multiple items for array updates.

$position

Modifies the $push operator to specify the position in the array to add elements.

$slice

Modifies the $push operator to limit the size of updated arrays.

$sort

Modifies the $push operator to reorder documents stored in an array.

$bit

Performs bitwise AND, OR, and XOR updates of integer values.