在MongoDb中更新多个内部文档

Question

在我的示例项目中，我在manager下有员工。Db模式是这样的;

{
"employees": [
{
"name": "Adam",
"_id": "5ea36b27d7ae560845afb88e",
"bananas": "allowed"
},
{
"name": "Smith",
"_id": "5ea36b27d7ae560845afb88f",
"bananas": "not-allowed"
},
{
"name": "John",
"_id": "5ea36b27d7ae560845afb88g",
"bananas": "not-allowed"
},
{
"name": "Patrick",
"_id": "5ea36b27d7ae560845afb88h",
"bananas": "allowed"
}
]
}

在本例中Adam允许吃香蕉和史密斯不是。如果我必须允许吃来自Adam的香蕉史密斯到我需要像这样执行两次更新操作:

db.managers.update(
{ 'employees.name': 'Adam' },
{ $set: { 'employees.$.bananas': 'not-allowed' } }
);

和

db.managers.update(
{ 'employees.name': 'Smith' },
{ $set: { 'employees.$.bananas': 'allowed' } }
);

是否可以在单个查询中处理此问题?

Answer 1

您可以使用$map和$cond根据员工的姓名对数组条目执行条件更新。$switch用于案例的潜在扩展。

db.collection.update({},
[
{
"$set": {
"employees": {
"$map": {
"input": "$employees",
"as": "e",
"in": {
"$switch": {
"branches": [
{
"case": {
$eq: [
"$$e.name",
"Adam"
]
},
"then": {
"$mergeObjects": [
"$$e",
{
"bananas": "not-allowed"
}
]
}
},
{
"case": {
$eq: [
"$$e.name",
"Smith"
]
},
"then": {
"$mergeObjects": [
"$$e",
{
"bananas": "allowed"
}
]
}
}
],
default: "$$e"
}
}
}
}
}
}
])

Mongo操场

Answer 2

db.managers.update(
{
$or: [
{"employees.name": "Adam"},
{"employees.name": "Smith"}
]
},
{
$set: {
"employees.$[e].bananas": {
$cond: [{ $eq: ["$e.name", "Adam"] }, "not-allowed", "allowed"]
}
}
},
{
arrayFilters: [{ "e.name": { $in: ["Adam", "Smith"] } }]
}
)