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MongoDB Limit fields and slice projection together?
Use the $slice operator. Let us first create a collection with documents −
> db.limitAndSliceProjectionDemo.insertOne(
{
"_id" : 101,
"UserName" : "Carol",
"UserAge" : 26,
"UserMesssage" : [
"Hi",
"Hello",
"Bye",
"Awesome",
"Good",
"Bad",
"Nice",
"Good Night",
"Good Morning"
]
}
);
{ "acknowledged" : true, "insertedId" : 101 }Following is the query to display all documents from a collection with the help of find() method −
> db.limitAndSliceProjectionDemo.find().pretty();
This will produce the following output −
{
"_id" : 101,
"UserName" : "Carol",
"UserAge" : 26,
"UserMesssage" : [
"Hi",
"Hello",
"Bye",
"Awesome",
"Good",
"Bad",
"Nice",
"Good Night",
"Good Morning"
]
}Following is the query to limit fields and perform slice projection together. Here, we are slicing from 2 to 4 −
> db.limitAndSliceProjectionDemo.find({ "UserName" : "Carol" }, {"_id": 0, "UserName":0,"UserAge":0, "UserMesssage": { "$slice": [2,4] } }).pretty();This will produce the following output −
{ "UserMesssage" : [ "Bye", "Awesome", "Good", "Bad" ] }
Updated on: 30-Jul-2019
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