MongoDB查询以查找FirstName和LastName的字段组合？
以下是要查询的字段组合查询-
> db.demo502.aggregate(
... [
... { "$redact": {
... "$cond": [
... { "$eq": [
... { "$concat": [ "$FirstName", " ", "$LastName" ] },
... "John Doe"
... ]},
... "$$KEEP",
... "$$PRUNE"
... ]
... }}
... ]
... )这将产生以下输出-
{ "_id" : ObjectId("5e875543987b6e0e9d18f56f"), "FirstName" : "John", "LastName" : "Doe" }