0These accumulators help find the smallest or largest value in a group of data. They make it easy to get minimum or maximum values from many records.
db.collection.aggregate([
{
$group: {
_id: null,
minValue: { $min: "$fieldName" },
maxValue: { $max: "$fieldName" }
}
}
])Use $min to get the smallest value and $max to get the largest value.
The $group stage groups documents; _id: null means all documents are grouped together.
db.sales.aggregate([
{
$group: {
_id: null,
minPrice: { $min: "$price" },
maxPrice: { $max: "$price" }
}
}
])db.students.aggregate([
{
$group: {
_id: "$class",
minScore: { $min: "$score" },
maxScore: { $max: "$score" }
}
}
])This example inserts some products with prices, then finds the lowest and highest price among them.
db.products.insertMany([
{ name: "Pen", price: 1.5 },
{ name: "Notebook", price: 3.0 },
{ name: "Eraser", price: 0.5 },
{ name: "Pencil", price: 1.0 }
])
db.products.aggregate([
{
$group: {
_id: null,
minPrice: { $min: "$price" },
maxPrice: { $max: "$price" }
}
}
])If the field contains non-numeric values, $min and $max will compare them based on BSON order.
Using _id: null groups all documents together; use a field name to group by categories.
$min finds the smallest value in a group.
$max finds the largest value in a group.
They are used inside the $group stage of aggregation.
$min and $max accumulators do in a MongoDB aggregation pipeline?$min and $max$min returns the smallest value from the grouped documents, while $max returns the largest value.$min and $max do.$min finds the smallest value and $max finds the largest value in a group. -> Option D$min = smallest, $max = largest [OK]$min and $max with average functions$max in a $group stage to find the highest score from a field named score?$max accumulator$max as the operator and the field name as a string with a $ prefix inside quotes: "$score".$max: "$field" syntax [OK]{ "name": "Alice", "score": 85 }, { "name": "Bob", "score": 92 }, { "name": "Charlie", "score": 78 }[{ $group: { _id: null, minScore: { $min: "$score" }, maxScore: { $max: "$score" } } }]$group stage groups all documents (_id: null) and calculates minScore as 78 and maxScore as 92.[{ $group: { _id: "$category", minPrice: { $min: price }, maxPrice: { $max: "$price" } } }]$min and $max usage$min accumulator uses price without quotes and $ prefix, which is incorrect. It should be "$price".$max is correctly used with "$price". Grouping by "$category" is valid. Using both accumulators together is allowed.region and amount. You want to find the smallest and largest sale amounts per region, but only for regions where the smallest sale is above 100. Which aggregation pipeline correctly achieves this?$group stage groups documents by region and calculates minSale and maxSale using $min and $max on amount.$match stage after grouping filters groups where minSale is greater than 100, exactly as required.Pass the test and this pattern moves unknown strong while earning +1 Grip toward your certificate.