$toObjectId
The $toObjectId operator converts an expression into an ObjectId
$toObjectId
The $toObject operator converts a specified value into an ObjectId.
Examples
Consider this sample document from the stores collection.
{
"_id": "0fcc0bf0-ed18-4ab8-b558-9848e18058f4",
"name": "First Up Consultants | Beverage Shop - Satterfieldmouth",
"location": {
"lat": -89.2384,
"lon": -46.4012
},
"staff": {
"totalStaff": {
"fullTime": 8,
"partTime": 20
}
},
"sales": {
"totalSales": 75670,
"salesByCategory": [
{
"categoryName": "Wine Accessories",
"totalSales": 34440
},
{
"categoryName": "Bitters",
"totalSales": 39496
},
{
"categoryName": "Rum",
"totalSales": 1734
}
]
},
"promotionEvents": [
{
"eventName": "Unbeatable Bargain Bash",
"promotionalDates": {
"startDate": {
"Year": 2024,
"Month": 6,
"Day": 23
},
"endDate": {
"Year": 2024,
"Month": 7,
"Day": 2
}
},
"discounts": [
{
"categoryName": "Whiskey",
"discountPercentage": 7
},
{
"categoryName": "Bitters",
"discountPercentage": 15
},
{
"categoryName": "Brandy",
"discountPercentage": 8
},
{
"categoryName": "Sports Drinks",
"discountPercentage": 22
},
{
"categoryName": "Vodka",
"discountPercentage": 19
}
]
},
{
"eventName": "Steal of a Deal Days",
"promotionalDates": {
"startDate": {
"Year": 2024,
"Month": 9,
"Day": 21
},
"endDate": {
"Year": 2024,
"Month": 9,
"Day": 29
}
},
"discounts": [
{
"categoryName": "Organic Wine",
"discountPercentage": 19
},
{
"categoryName": "White Wine",
"discountPercentage": 20
},
{
"categoryName": "Sparkling Wine",
"discountPercentage": 19
},
{
"categoryName": "Whiskey",
"discountPercentage": 17
},
{
"categoryName": "Vodka",
"discountPercentage": 23
}
]
}
]
}Example 1: Convert the first 24 alphanumeric characters in the _id field into an ObjectId value
To remove all occurrences of the "-" character and convert the first twenty four characters in the _id field into an ObjectId, run a query using the $toObjectId on a substring of the modified _id field to make the conversion.
db.stores.aggregate([{
$match: {
_id: "b0107631-9370-4acd-aafa-8ac3511e623d"
}
}, {
$project: {
idAsObjectId: {
$toObjectId: {
$substr: [{
$replaceAll: {
input: "$_id",
find: "-",
replacement: ""
}
}, 0, 24]
}
}
}
}])This query returns the following result:
[
{
"_id": "b0107631-9370-4acd-aafa-8ac3511e623d",
"idAsObjectId": "ObjectId('b010763193704acdaafa8ac3')"
}
]