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MongoDB query to find on field combination of FirstName and LastName?
For combination, use $concat and check the equality using $eq. Let us create a collection with documents −
> db.demo502.insertOne({"FirstName":"John","LastName":"Smith"});{
"acknowledged" : true,
"insertedId" : ObjectId("5e875534987b6e0e9d18f56d")
}
> db.demo502.insertOne({"FirstName":"David","LastName":"Miller"});{
"acknowledged" : true,
"insertedId" : ObjectId("5e87553e987b6e0e9d18f56e")
}
> db.demo502.insertOne({"FirstName":"John","LastName":"Doe"});{
"acknowledged" : true,
"insertedId" : ObjectId("5e875543987b6e0e9d18f56f")
}Display all documents from a collection with the help of find() method −
> db.demo502.find();
This will produce the following output −
{ "_id" : ObjectId("5e875534987b6e0e9d18f56d"), "FirstName" : "John", "LastName" : "Smith"
}
{ "_id" : ObjectId("5e87553e987b6e0e9d18f56e"), "FirstName" : "David", "LastName" : "Miller"
}
{ "_id" : ObjectId("5e875543987b6e0e9d18f56f"), "FirstName" : "John", "LastName" : "Doe" }Following is the query to find on field combination −
> db.demo502.aggregate(
... [
... { "$redact": {
... "$cond": [
... { "$eq": [
... { "$concat": [ "$FirstName", " ", "$LastName" ] },
... "John Doe"
... ]},
... "$$KEEP",
... "$$PRUNE"
... ]
... }}
... ]
... )This will produce the following output −
{ "_id" : ObjectId("5e875543987b6e0e9d18f56f"), "FirstName" : "John", "LastName" : "Doe" }
Updated on: 13-May-2020
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