C
C#•3y ago
M B V R K

EF Core Global Query Filter with Nullable Exception

Hi friends, I'm try to create a Global query filter for my EF Core, to be honest this is the first time for me with Global Query Filters In my AppDbContext => OnModelCreating I tried this: 
  foreach ( var entityType in modelBuilder.Model.GetEntityTypes() )
        {
            if ( typeof( IArchivable ).IsAssignableFrom( entityType.ClrType ) )
            {
                var parameter = Expression.Parameter( entityType.ClrType , "p" );
                var archivedCheck = Expression.Lambda(Expression.Equal(Expression.Property(parameter, "IsArchived"), Expression.Constant(false)), parameter);
                modelBuilder.Entity( entityType.ClrType ).HasQueryFilter( archivedCheck );
            }
        }
  foreach ( var entityType in modelBuilder.Model.GetEntityTypes() )
        {
            if ( typeof( IArchivable ).IsAssignableFrom( entityType.ClrType ) )
            {
                var parameter = Expression.Parameter( entityType.ClrType , "p" );
                var archivedCheck = Expression.Lambda(Expression.Equal(Expression.Property(parameter, "IsArchived"), Expression.Constant(false)), parameter);
                modelBuilder.Entity( entityType.ClrType ).HasQueryFilter( archivedCheck );
            }
        }
How my IArchivable looks like: 
    public interface IArchivable
    {
        bool?     IsArchived { get; set; }
        string    ArchivedBy { get; set; }
        DateTime? ArchivedOn { get; set; }
    }
    public interface IArchivable
    {
        bool?     IsArchived { get; set; }
        string    ArchivedBy { get; set; }
        DateTime? ArchivedOn { get; set; }
    }
The Issue: When I start the app, automatically II get this exception:
InvalidOperationException: The binary operator Equal is not defined for the types 'System.Nullable`1[System.Boolean]' and 'System.Boolean'.
I think the issue related with the Nullable IsArchived property, may I need to add an OR to my Expression, My Questions: What is the cause of that issue? If the Nullable of the IsArchived how to fix it ? If I need to ad an OR to my expression to check the Nullability of ISArchived how to do it ? Massive thanks in advance <3
1 Reply
M B V R K
M B V R KOP•3y ago
Screenshot of the Exception:

Did you find this page helpful?