CODEWITHSUNDEEP
mongodbpull
Akhilesh Ojha
Akhilesh Ojha

Reputation: 33

$pull operator in MongoDB

{
    "_id" : ObjectId("5badfada90fd543fd8aa7f96"),
    "__v" : 0,
    "deleted" : false,
    "groups" : [ 
        {
            "group" : "grp",
            "_id" : ObjectId("5bae09a601123357e58b66a2"),
            "activities" : [ 
                ObjectId("5bae09a601123357e58b66a3"), 
                ObjectId("5bae10de01123357e58b66a6")
            ]
        }, 
        {
            "group" : "123",
            "_id" : ObjectId("5bae0f1001123357e58b66a4"),
            "activities" : [ 
                ObjectId("5bae0f1001123357e58b66a5")
            ]
        }
    ],
    "nextActivityId" : 22,
    "name" : "test",
    "year" : "1",
    "status" : "2",
    "vision" : ObjectId("5bab2f4872acf42a81c124d0")
}

The Above Schema is a "Plan" Schema I have to write a query for removing an Activity inside "activities" array. What will be the optimum solution for this? And how will I use $pull to achieve this This was my solution, but it will delete the complete groups array

Plan.update({ _id: PLAN ID }, { $pull: { groups: { activities: ACTIVITY ID } } })

PLAN ID BEING: "_id" : ObjectId("5badfada90fd543fd8aa7f96"), ACTIVITY ID FOR EXAMPLE BEING: ObjectId("5bae09a601123357e58b66a3")

Thank you!

Upvotes: 0

Views: 282

Answers (2)

nercan
nercan

Reputation: 207

You can try this,

    db.Plan.update({ _id: ObjectId("5badfada90fd543fd8aa7f96"),"groups.activities":{$in:[ ObjectId("5bae09a601123357e58b66a3") ]}},
{ $pull: { "groups.$.activities": ObjectId("5bae09a601123357e58b66a3") }  });

The positional operator did not find the match needed from the query warning when use $ only update object.

Upvotes: 0

Marco
Marco

Reputation: 761

You need to use the positional $ update operator.

db.Plan.update(
    { "_id" : PLAN ID }, 
    { "$pull": { "groups.$.activities": ACTIVITY ID } } 
)

Upvotes: 1

Related Questions