Query Document Examples

• Valid queries on a text field:

{employee:”Bob”}

{ employee : “Bob” }

{ ‘employee’ : “Bob” }

{ “employee” : “Bob” }

• Invalid query on a text field:

{ employee : Bob }

• Valid queries on a numeric field:

{salary:50000}

{ salary : {$gt:30000} }

• Invalid query on a numeric field:

{ salary : “50000” }

• Valid query on an array field:

{ rating: {$elemMatch: {$lt: 5}} }

This is the syntax for, Single element satisfies the criteria. This query looks for a document where the rating array contains at least one value that is less than 5

• Invalid query on an array field:

{ rating: 5 }  

• Special invalid case:

{_id: "53ac6148a4a4be23e92bb6f1"}

This is an invalid query, because _id is an ObjectId object created by MongoDB that cannot be matched to a string.