$each (array update)
APPLIES TO: MongoDB vCore
The $each
operator is used within an $addToSet
or $push
operation to add multiple elements to an array field in a single update operation. This operator is useful when you need to insert multiple items into an array without having to perform multiple update operations. The $each
operator ensures that each item in the specified array is added to the target array.
Syntax
{
$push: {
<field>: {
$each: [ <value1>, <value2>, ... ],
<modifier1>: <value1>,
<modifier2>: <value2>,
...
}
}
}
Parameters
Description | |
---|---|
<field> |
The field to be updated. |
$each |
An array of values to be added to the array field. |
<modifier> |
Optional modifiers like $sort , $slice , and $position to control the behavior of the $push operation. |
Example
Let's understand the usage with the following sample json.
{
"_id": "7954bd5c-9ac2-4c10-bb7a-2b79bd0963c5",
"name": "Lakeshore Retail | DJ Equipment Stop - Port Cecile",
"location": {
"lat": 60.1441,
"lon": -141.5012
},
"staff": {
"totalStaff": {
"fullTime": 2,
"partTime": 0
}
},
"sales": {
"salesByCategory": [
{
"categoryName": "DJ Headphones",
"totalSales": 35921
}
],
"fullSales": 3700
},
"promotionEvents": [
{
"eventName": "Bargain Blitz Days",
"promotionalDates": {
"startDate": {
"Year": 2024,
"Month": 3,
"Day": 11
},
"endDate": {
"Year": 2024,
"Month": 2,
"Day": 18
}
},
"discounts": [
{
"categoryName": "DJ Turntables",
"discountPercentage": 18
},
{
"categoryName": "DJ Mixers",
"discountPercentage": 15
}
]
}
],
"tag": [
"#ShopLocal",
"#SeasonalSale",
"#FreeShipping",
"#MembershipDeals"
]
}
To add multiple new promotion events to the promotionEvents
array.
db.stores.updateOne(
{ "name": "Lenore's New DJ Equipment Store" },
{
$push: {
promotionEvents: {
$each: [
{
eventName: "Grand Savings",
promotionalDates: {
startDate: "2024-08-01",
endDate: "2024-08-31"
},
discounts: [
{
categoryName: "DJ Headphones",
discountPercentage: 5
}
]
},
{
eventName: "Big Bargain",
promotionalDates: {
startDate: "2024-11-25",
endDate: "2024-11-30"
},
discounts: [
{
categoryName: "DJ Headphones",
discountPercentage: 20
}
]
}
]
}
}
}
)
This query would return the following document.
{
"acknowledged": true,
"insertedId": null,
"matchedCount": "0",
"modifiedCount": "0",
"upsertedCount": 0
}
Related content
- Review options for Migrating from MongoDB to Azure Cosmos DB for MongoDB (vCore)
- Read more about Feature compatibility with MongoDB