Oracle & Mongo Database

MongoDB Operators

Fields Description

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

$inc à Increments the value of the field by the specified amount.

$min à Only updates the field if the specified value is less than the existing field value.

$max à Only updates the field if the specified value is greater than the existing field value.

$mul à Multiplies the value of the field by the specified amount.

$rename à Renames a field.

$set à Sets the value of a field in a document.

$setOnInsert à 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 à Removes the specified field from a document.

Array Operators

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

$addToSet à Adds elements to an array only if they do not already exist in the set.

$pop à Removes the first or last item of an array.

$pull à removes all array elements that match a specified query.

$pushAll à Deprecated. Adds several items to an array.

$push à Adds an item to an array.

$pullAll à Removes all matching values from an array.

Modifiers

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

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

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

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

Partial Update

$set Parameter

> db.sai.find()

{ "_id" : ObjectId("59f034e02559518339882775"), "a" :

{ "_id" : ObjectId("59f035092559518339882776"), "a" :

{ "_id" : 2, "a" : 42, "b" : "said", "dafa" : 232, "s

a=db.sai

a.insert({_id:1},{"name":"sai"})

$inc

> db.sai.insert({_id:3},{inc_sai:100})

WriteResult({ "nInserted" : 1 })

> db.sai.find({_id:3})

{ "_id" : 3 }

> db.sai.insert({_id:3},{$inc{inc_sai:100})

> db.sai.update({_id:3},{$inc:{inc_sai:1}})