适用对象：
MongoDB vCore
运算符 $lt 用于匹配字段的值严格小于指定值的文档。 运算符 $lt 基于数字、日期或字符串值筛选文档。
语法
在 MongoDB 查询中使用 $lt 运算符的语法为：
{ "field": { "$lt": value } }
参数
| 参数 | DESCRIPTION |
|---|---|
field |
要评估的文档中的字段 |
value |
要与字段值进行比较的值。 运算符将匹配字段值小于此指定值的文档 |
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：查找总销售额小于 $36000 的商店
db.stores.find({"sales.totalSales": { "$lt": 36000 }}, {"name": 1, "sales.totalSales": 1}, {"limit": 1})
这会返回以下结果：
{
"_id": "e6895a31-a5cd-4103-8889-3b95a864e5a6",
"name": "VanArsdel, Ltd. | Picture Frame Store - Port Clevelandton",
"sales": { "totalSales": 17676 }
}