适用对象：
MongoDB vCore
运算符 $in 用于将字段的值与可能值的数组匹配。 运算符 $in 筛选出字段值等于指定的数值的文档。
语法
{ field: { $in: [<value1>, <value2>, ... <valueN>] } }
参数
| 参数 | DESCRIPTION |
|---|---|
field |
要匹配的字段 |
[<value1>, <value2>, ... <valueN>] |
一个用于与指定字段进行比较的值数组 |
例子
请查看 StoreData 数据库中 stores 集合的这个示例文档。
{
"_id": "0fcc0bf0-ed18-4ab8-b558-9848e18058f4",
"name": "First Up Consultants | Beverage Shop - Satterfieldmouth",
"location": {
"lat": -89.2384,
"lon": -46.4012
},
"staff": {
"totalStaff": {
"fullTime": 8,
"partTime": 20
}
},
"sales": {
"totalSales": 75670,
"salesByCategory": [
{
"categoryName": "Wine Accessories",
"totalSales": 34440
},
{
"categoryName": "Bitters",
"totalSales": 39496
},
{
"categoryName": "Rum",
"totalSales": 1734
}
]
},
"promotionEvents": [
{
"eventName": "Unbeatable Bargain Bash",
"promotionalDates": {
"startDate": {
"Year": 2024,
"Month": 6,
"Day": 23
},
"endDate": {
"Year": 2024,
"Month": 7,
"Day": 2
}
},
"discounts": [
{
"categoryName": "Whiskey",
"discountPercentage": 7
},
{
"categoryName": "Bitters",
"discountPercentage": 15
},
{
"categoryName": "Brandy",
"discountPercentage": 8
},
{
"categoryName": "Sports Drinks",
"discountPercentage": 22
},
{
"categoryName": "Vodka",
"discountPercentage": 19
}
]
},
{
"eventName": "Steal of a Deal Days",
"promotionalDates": {
"startDate": {
"Year": 2024,
"Month": 9,
"Day": 21
},
"endDate": {
"Year": 2024,
"Month": 9,
"Day": 29
}
},
"discounts": [
{
"categoryName": "Organic Wine",
"discountPercentage": 19
},
{
"categoryName": "White Wine",
"discountPercentage": 20
},
{
"categoryName": "Sparkling Wine",
"discountPercentage": 19
},
{
"categoryName": "Whiskey",
"discountPercentage": 17
},
{
"categoryName": "Vodka",
"discountPercentage": 23
}
]
}
]
}
示例 1 - 查找包含促销活动的文档，其折扣百分比为 10%、15% 或 20%
db.stores.find({ "promotionEvents.discounts.discountPercentage": { "$in": [10, 15, 20] }}, {"name": 1, "promotionEvents.discounts.discountPercentage": 1}, {"limit": 1})
这会返回以下结果：
{
"_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74",
"name": "Proseware, Inc. | Home Entertainment Hub - East Linwoodbury",
"promotionEvents": [
{
"discounts": [
{ "discountPercentage": 14 },
{ "discountPercentage": 6 },
{ "discountPercentage": 21 },
{ "discountPercentage": 21 },
{ "discountPercentage": 5 },
{ "discountPercentage": 22 }
]
}
]
}
示例 2 - 查找含有特定类别打折优惠的促销文档
db.stores.find({ "promotionEvents.discounts.categoryName": { "$in": ["Smoked Salmon", "Anklets"] }}, {"name": 1, "promotionEvents.discounts.categoryName": 1}, {"limit": 1})
这会返回以下结果：
{
"_id": "3f140a3f-6809-4b40-85b1-75657f5605b8",
"name": "Boulder Innovations | Jewelry Store - Littleborough",
"promotionEvents": [
{
"discounts": [ { "categoryName": "Watches" }, { "categoryName": "Rings" } ]
},
{
"discounts": [ { "categoryName": "Anklets" }, { "categoryName": "Earrings" } ]
},
{
"discounts": [ { "categoryName": "Rings" }, { "categoryName": "Anklets" } ]
},
{
"discounts": [ { "categoryName": "Earrings" }, { "categoryName": "Necklaces" } ]
},
{
"discounts": [ { "categoryName": "Charms" }, { "categoryName": "Bracelets" } ]
},
{
"discounts": [ { "categoryName": "Watches" }, { "categoryName": "Brooches" } ]
}
]
}