适用对象：
MongoDB vCore
findAndModify 命令用于以原子方式修改和返回单个文档。 此命令对于需要通过一个步骤读取和更新文档的操作很有用，可确保数据一致性。 常见用例包括实现计数器、队列和其他原子操作。
语法
findAndModify 命令的语法如下：
db.collection.findAndModify({
query: <document>,
sort: <document>,
remove: <boolean>,
update: <document>,
new: <boolean>,
fields: <document>,
upsert: <boolean>
})
参数
- query：要修改的文档的选择条件。
- sort：如果查询选择多个文档，则确定要修改哪个文档。
- remove：如果为
true，则删除所选文档。 - update：要应用的修改。
- new：如果为
true，则返回修改后的文档，而不是原始文档。 - fields：限制要对匹配文档返回的字段。
- upsert：如果为
true，则当没有文档与查询匹配时，创建一个新文档。
示例
示例 1：更新总销售额
假设我们要将 _id 为“e5767a9f-cd95-439c-9ec4-7ddc13d22926”的商店的总销售额更新为 550000.00 并返回更新后的文档。
db.stores.findAndModify({
query: { "_id": "e5767a9f-cd95-439c-9ec4-7ddc13d22926" },
update: { $set: { "sales.totalSales": 550000.00 } },
new: true
})
示例输出
[mongos] StoreData> db.stores.findAndModify({
... query: { "_id": "e5767a9f-cd95-439c-9ec4-7ddc13d22926" },
... update: { $set: { "sales.totalSales": 550000.00 } },
... new: true
... })
{
_id: 'e5767a9f-cd95-439c-9ec4-7ddc13d22926',
name: "Marina's Eyewear Bargains",
location: { lat: -87.4376, lon: 42.2928 },
staff: { totalStaff: { fullTime: 20, partTime: 6 } },
sales: {
totalSales: 550000,
salesByCategory: [
{ categoryName: 'Round Sunglasses', totalSales: 39621 },
{ categoryName: 'Reading Glasses', totalSales: 1146 },
{ categoryName: 'Aviators', totalSales: 9385 }
]
},
promotionEvents: [
{
eventName: 'Incredible Discount Days',
promotionalDates: {
startDate: { Year: 2024, Month: 2, Day: 11 },
endDate: { Year: 2024, Month: 2, Day: 18 }
},
discounts: [
{ categoryName: 'Square Sunglasses', discountPercentage: 16 },
{ categoryName: 'Safety Glasses', discountPercentage: 17 },
{ categoryName: 'Wayfarers', discountPercentage: 7 },
{ categoryName: 'Eyewear Accessories', discountPercentage: 12 }
]
}
],
tag: [
'#ShopLocal',
'#FashionStore',
'#SeasonalSale',
'#FreeShipping',
'#MembershipDeals'
]
}
示例 2：添加新的促销活动
让我们向 _id_ 为“e5767a9f-cd95-439c-9ec4-7ddc13d22926”的商店添加一个名为“电子产品超值优惠”的新促销活动，并返回更新后的文档。
db.stores.findAndModify({
query: { "_id": "e5767a9f-cd95-439c-9ec4-7ddc13d22926" },
update: { $push: { "promotionEvents": {
"eventName": "Electronics Super Saver",
"promotionalDates": {
"startDate": "2025-09-31",
"endDate": "2025-09-31"
},
"discounts": [
{
"categoryName": "Laptops",
"discountPercentage": 45
},
{
"categoryName": "Smartphones",
"discountPercentage": 25
}
]
}}},
new: true
})
示例输出
[mongos] StoreData> db.stores.findAndModify({
... query: { "_id": "e5767a9f-cd95-439c-9ec4-7ddc13d22926" },
... update: { $push: { "promotionEvents": {
... "eventName": "Electronics Super Saver",
... "promotionalDates": {
... "startDate": "2025-09-31",
... "endDate": "2025-09-31"
... },
... "discounts": [
... {
... "categoryName": "Laptops",
... "discountPercentage": 45
... },
... {
... "categoryName": "Smartphones",
... "discountPercentage": 25
... }
... ]
... }}},
... new: true
... })
{
_id: 'e5767a9f-cd95-439c-9ec4-7ddc13d22926',
name: "Marina's Eyewear Bargains",
location: { lat: -87.4376, lon: 42.2928 },
staff: { totalStaff: { fullTime: 20, partTime: 6 } },
sales: {
totalSales: 550000,
salesByCategory: [
{ categoryName: 'Round Sunglasses', totalSales: 39621 },
{ categoryName: 'Reading Glasses', totalSales: 1146 },
{ categoryName: 'Aviators', totalSales: 9385 }
]
},
promotionEvents: [
{
eventName: 'Electronics Super Saver',
promotionalDates: { startDate: '2025-09-31', endDate: '2025-09-31' },
discounts: [
{ categoryName: 'Laptops', discountPercentage: 45 },
{ categoryName: 'Smartphones', discountPercentage: 25 }
]
}
],
tag: [
'#ShopLocal',
'#FashionStore',
'#SeasonalSale',
'#FreeShipping',
'#MembershipDeals'
]
}
示例 3：删除促销活动
假设我们要从 _id 为“e5767a9f-cd95-439c-9ec4-7ddc13d22926”的商店中删除“电子产品超值优惠”促销活动并返回原始文档。
db.stores.findAndModify({
query: { "_id": "e5767a9f-cd95-439c-9ec4-7ddc13d22926" },
update: { $pull: { "promotionEvents": { "eventName": "Electronics Super Saver" } } },
new: true
})
示例输出
[mongos] StoreData> db.stores.findAndModify({
... query: { "_id_": "e5767a9f-cd95-439c-9ec4-7ddc13d22926" },
... update: { $pull: { "promotionEvents": { "eventName": "Electronics Super Saver" } } },
... new: true
... })
null
[mongos] StoreData> db.stores.findAndModify({
... query: { "_id": "e5767a9f-cd95-439c-9ec4-7ddc13d22926" },
... update: { $pull: { "promotionEvents": { "eventName": "Electronics Super Saver" } } },
... new: true
... })
{
_id: 'e5767a9f-cd95-439c-9ec4-7ddc13d22926',
name: "Marina's Eyewear Bargains",
location: { lat: -87.4376, lon: 42.2928 },
staff: { totalStaff: { fullTime: 20, partTime: 6 } },
sales: {
totalSales: 550000,
salesByCategory: [
{ categoryName: 'Round Sunglasses', totalSales: 39621 },
{ categoryName: 'Reading Glasses', totalSales: 1146 },
{ categoryName: 'Aviators', totalSales: 9385 }
]
},
promotionEvents: [
{
eventName: 'Incredible Discount Days',
promotionalDates: {
startDate: { Year: 2024, Month: 2, Day: 11 },
endDate: { Year: 2024, Month: 2, Day: 18 }
},
discounts: [
{ categoryName: 'Square Sunglasses', discountPercentage: 16 },
{ categoryName: 'Safety Glasses', discountPercentage: 17 },
{ categoryName: 'Wayfarers', discountPercentage: 7 },
{ categoryName: 'Eyewear Accessories', discountPercentage: 12 }
]
}
],
tag: [
'#ShopLocal',
'#FashionStore',
'#SeasonalSale',
'#FreeShipping',
'#MembershipDeals'
]
}