room error: The columns returned by the query does not have the fields fieldname

Question

Here is a sample POJO

public class Product{
  private long id;
  private String name;
  private double price;

 ... constructor for all fields
 ... getters a         


        

Answer 1

Primitive types are by default not null. Make the price Double and this will solve the issue since it will be nullable then. Furthermore, you can add a custom getter to avoid having price as a null object.

public double getPrice(){
    if(this.price == null) return 0.0;
    return this.price;
}

@Ingore tells Room to ignore the field altogether, which is not what you want, based on your answer.