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How can I use $elemMatch on first level array in MongoDB?
You can use $in operator instead of $elemMatch on first level array. The syntax is as follows
db.yourCollectionName.find({yourFieldName:{$in:["yourValue"]}}).pretty();Let us first create a collection with documents
>db.firstLevelArrayDemo.insertOne({"StudentName":"Chris","StudentTechnicalSkills":["Mongo
DB","MySQL","SQL Server"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ca2360f66324ffac2a7dc71")
}
>db.firstLevelArrayDemo.insertOne({"StudentName":"Robert","StudentTechnicalSkills":["C","J
ava","C++"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ca2362766324ffac2a7dc72")
}Following is the query to display all documents from a collection with the help of find() method
> db.firstLevelArrayDemo.find().pretty();
This will produce the following output
{
"_id" : ObjectId("5ca2360f66324ffac2a7dc71"),
"StudentName" : "Chris",
"StudentTechnicalSkills" : [
"MongoDB",
"MySQL",
"SQL Server"
]
}
{
"_id" : ObjectId("5ca2362766324ffac2a7dc72"),
"StudentName" : "Robert",
"StudentTechnicalSkills" : [
"C",
"Java",
"C++"
]
}Following is the query to match on first level array
> db.firstLevelArrayDemo.find({StudentTechnicalSkills:{$in:["MongoDB"]}}).pretty();This will produce the following output
{
"_id" : ObjectId("5ca2360f66324ffac2a7dc71"),
"StudentName" : "Chris",
"StudentTechnicalSkills" : [
"MongoDB",
"MySQL",
"SQL Server"
]
}
Updated on: 30-Jul-2019
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