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How to improve querying field in MongoDB?
To improve querying field in MongoDB, you need to use index. Let us create a collection with documents
> db.improveQueryDemo.insertOne(
... {
... "PlayerDetails":[
... {"PlayerName": "John", "PlayerGameScore": 5690},
... {"PlayerName": "Carol", "PlayerGameScore": 2690},
... ]
... }
... );
{
"acknowledged" : true,
"insertedId" : ObjectId("5c9dbaf875e2eeda1d5c3670")
}Following is the query to display all documents from a collection with the help of find() method
> db.improveQueryDemo.find().pretty();
This will produce the following output
{
"_id" : ObjectId("5c9dbaf875e2eeda1d5c3670"),
"PlayerDetails" : [
{
"PlayerName" : "John",
"PlayerGameScore" : 5690
},
{
"PlayerName" : "Carol",
"PlayerGameScore" : 2690
}
]
}Now you need to create an index on the field to improve querying. Following is the query
> db.improveQueryDemo.ensureIndex({"PlayerDetails.PlayerName":1});This will produce the following output
{
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 1,
"numIndexesAfter" : 2,
"ok" : 1
}Now you can search by the exact match. Following is the query
> db.improveQueryDemo.find({"PlayerDetails.PlayerName":"Carol"}).pretty();This will produce the following output
{
"_id" : ObjectId("5c9dbaf875e2eeda1d5c3670"),
"PlayerDetails" : [
{
"PlayerName" : "John",
"PlayerGameScore" : 5690
},
{
"PlayerName" : "Carol",
"PlayerGameScore" : 2690
}
]
}
Updated on: 30-Jul-2019
66 Views
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