MongoDB playground All In One
MongoDB REPL
db={
"teacher": [
{
"_id": ObjectId("64fee9b54273ac2234441225"),
"teacherid": ObjectId("64f1d72a4331bc8fc4c5930f"),
"name": "xgqfrms"
}
],
"users": [
{
_id: ObjectId("64f1d72a4331bc8fc4c5930f"),
name: "eric"
}
]
}
aggregate
db.teacher.aggregate([
{
$match: {
"teacherid": ObjectId("64f1d72a4331bc8fc4c5930f")
}
},
{
$lookup: {
from: "users",
localField: "teacherid",
foreignField: "_id",
as: "student"
}
},
{
$unset: "name"
}
])
// ]).explain()
// ]).pretty()
// Unsupported method: only find(), aggregate(), update() and explain() are supported
demos
mongo
$ mongo
# replace the `YOUR_DATABASE_NAME` with your real database name.
> use YOUR_DATABASE_NAME
# update Teacher collection ✅
> db.Teacher.update(
{"teacherid" : "64f1d72a4331bc8fc4c5930f"},
{
$set: {"teacherid" : ObjectId("64f1d72a4331bc8fc4c5930f")}
});
> db.Teacher.aggregate([
{
$match: {
"teacherid": ObjectId("64f1d72a4331bc8fc4c5930f")
}
},
{
$lookup: {
from: "user",
localField: "teacherid",
foreignField: "_id",
as: "student"
}
},
{
$unset: "name"
}
]).pretty();
Node.js
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MongoDB 跨表查询
https://www.cnblogs.com/xgqfrms/p/17724984.html#5215297
refs
https://www.cnblogs.com/xgqfrms/p/17724984.html#5215324
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