MongoDB array update operation

Update single array element

Demo data:



{
name:"codelearningpoint",
skills:[
   { name:"Nodejs" , key:"nodejs"},
   { name:"MongoDB" , key:"mongodb"}
 ]
}

1. I want to update exact { name:"Nodejs" , key:"nodejs"} array element.

db.collection.updateOne(
  { "skills.key" : 'nodejs' },
 { 
   $set : {"skills.$": { name:"React" , key : "react"} }
 }
)

Output : $ refers to the exact matched first element.


{
name:"codelearningpoint",
skills:[
   { name:"React" , key:"react"},
   { name:"MongoDB" , key:"mongodb"}
 ]
}

2. I want to add active : true property to all the skills , how to do that ?

db.collection.updateMany(
  { $or:[{key:"mongodb"},{key:"nodejs"}] },
 { 
   $set : {"skills.$.active": true }
 }
)

Output : It did not update all the documents

Reason $ sign only refers to the first match element. that is why it has updated only the first element.

Note : if filter is empty the we can not use $

{
name:"codelearningpoint",
skills:[
   { name:"React" , key:"react" , active : true},
   { name:"MongoDB" , key:"mongodb" }
 ]
}

Update All array element

In order to achieve that we need use $[] , $[] refers to all the element of the array

db.collection.updateMany(
  { $or:[{key:"mongodb"},{key:"nodejs"}] },
 { 
   $set : {"skills.$[].active": true }
 }
)

db.collection.updateMany(
 {},
 { 
   $set : {"skills.$[].active": true }
 }
)

Output:

{
name:"codelearningpoint",
skills:[
   { name:"React" , key:"react" , active : true},
   { name:"MongoDB" , key:"mongodb" , active : true}
 ]
}

Finding and updating specific fields (filterArrays)

Demo Data

{
key: 'brand',
    displayName: 'Brand',
    options: [
      {
        key: 'samsung',
        displayName: 'Samsung',
        count: 0,
        selected: false,
        active: true
      },
      {
        key: 'lg',
        displayName: 'LG',
        count: 0,
        selected: false,
        active: true,
      },
      {
        key: 'nokia',
        displayName: 'Nokia',
        count: 0,
        selected: false,
        active: true
      },
      {
        key: 'apple',
        displayName: 'Apple',
        count: 0,
        selected: false,
        active: true
      }
    ]
}

1. I want to add one new property {bestBrand : true} to the options array element if the key matches.

db.collection.updateOne(
    {
        $or:[
            {"options.key":"apple"},
            {"options.key":"lg"}]
    },
    {$set:
        {"options.$[el].bestBrand":true}
    },
    {
        arrayFilters:[
        {
            $or:[{"el.key":"apple"},{"el.key":"lg"}]
        }
        ]
    }
)

Note : The main filter and the arrayFilter can be different.

el is used as an identifier used for the arrayFilters[] condition.

Update 3 layer nested array in mongoDB

{
   "_id" : 1,
   "grades" : [
      { "type" : "quiz1", "questions" : [ 1, 10, 5 ] },
      { "type" : "quiz2", "questions" : [ 10, 11, 6 ] },
      { "type" : "quiz3", "questions" : [ 5, 4, 3 ] },
      { "type" : "quiz4", "questions" : [ 2, 10, 23, 0 ] }
   ]
}

> Update all the grade elements

> if the questions value id greater than equal 6 then the value will be increased by 1

db.collection.updateMany(
   {},
   { $inc: { "grades.$[].questions.$[score]": 1 } },
   { arrayFilters: [  { "score": { $gte: 6 } } ] }
)

> Increment all the questions value by 1 if the grade type is quiz2

db.collection.updateMany(
   {},
   { $inc: { "grades.$[el].questions.$[score]": 1 } },
   { arrayFilters: [ { "el.type": "quiz" }, { "score": { $gte: 6 } } ] }
)

How to add elements to array in mongoDB

How to add single element to array ?

db.collection.updateOne(
{"skills.key":"nodejs"},
{$push : {"skills":{ name:"HTML" , key:"html" }}
}
)

How to add multiple element to array ?

db.collection.updateOne(
{"skills.key":"nodejs"},
{
 $push : {
     "skills":{ $each:[ { name:"HTML" , key:"html" },{ name:"CSS" , key:"css" } ]  }
  }
}
)

Sort array elements while adding to array.

db.collection.updateOne(
{"skills.key":"nodejs"},
{
 $push : {
     "skills":{ $each:[ { name:"HTML" , key:"html" },{ name:"CSS" , key:"css" } ] , $sort: { name: -1 } }
  }
}
)

While adding i want to avoid pushing duplicate elements , for that i we will use $addToSet

db.collection.updateOne(
{"skills.key":"nodejs"},
{
 $addToSet : { "skills":{ name:"HTML" , key:"html" }}
}
)

How to remove element from array in mongoDB

Demo data:


{
name:"codelearningpoint",
skills:[
   { name:"Nodejs" , key:"nodejs"},
   { name:"MongoDB" , key:"mongodb"}
 ]
}

1. I want to remove an element from skills array if the key is nodejs.

$pull helps to remove the element , in {$pull : { skills : {key : "nodejs"}}} { skills : {key : "nodejs"}} is the condition or we can use any filter operators here.

{ $pull: { <field1>: <value||condition>, <field2>: <value||condition> } }

db.collection.updateOne(
{"skills.key" : "nodejs"},
{$pull : { skills : {key : "nodejs"}}}
)

Output :

{
name:"codelearningpoint",
skills:[
   { name:"MongoDB" , key:"mongodb"}
 ]
}

2. I want to remove the last element from skills array

db.collection.updateOne(
{"skills.key" : "nodejs"},
{$pop : { skills : 1 }}
)

Output :

{
name:"codelearningpoint",
skills:[
   { name:"Nodejs" , key:"nodejs"}
 ]
}

3. I want to remove first element from skills array

db.collection.updateOne(
{"skills.key" : "nodejs"},
{$pull : { skills : -1 }}
)

Output :

{
name:"codelearningpoint",
skills:[
   { name:"MongoDB" , key:"mongodb"}
 ]
}

Note : Skills : -1 , will remove the first element from skills array and skills:1 will remove the last element from skills array.

Multiple operations at same time

Demo data :

{
name:"codelearningpoint",
skills:[
   { name:"Nodejs" , key:"nodejs"},
   { name:"MongoDB" , key:"mongodb"}
 ]
}

Fins the document and add new test:true property and delete the nodejs object

db.collection.updateOne({"skills.key":'nodejs'}, {$set: {test:true}, $pull:{ skills :{ key: 'nodejs'} } } )

Output :

{
name:"codelearningpoint",
test:true,
skills:[
{ name:"MongoDB" , key:"mongodb"}
 ]
}

MongoDB array update operation