The INSERT statement conflicted with the FOREIGN KEY constraint in Entity framework core, 2 tables in single statement

I have following 2 classes.

public partial class Query
{
    public int Id { get; set; }
    public virtual QueryGroup QueryGroup { get; set; }
}


public partial class QueryGroup
{
    public int Id { get; set; }
    public virtual ICollection<Query> Query { get; set; }
}

Now these 2 classes are parsed from json. so both Ids are 0, because it is adding (not updating).

When I do below.

projectContext.SaveChanges();

It gives below error, how to add them both in single statement. or will it require seperate add?

SqlException: The INSERT statement conflicted with the FOREIGN KEY constraint "FK_Query_QueryGroup". The conflict occurred in database "Project", table "dbo.QueryGroup", column 'Id'.