Model is not a constructor

Please help me with this issue.When i make the following api call i am getting the error as ;Model is not a constructor’
var query = new Backendless.DataQuery();
query.condition = ‘UniqueId=’+providerID;
var providedStudent = Backendless.Persistence.of(‘Student’).find(query).data;

The argument of the of() method must not be String, it should be a constructor function.

Also, there is a problem in your query.condition. The providerID value must be surrounded by single quotes.