How to create default filters with entity framework 6?

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I have an Exclude field in several classes and when I go to do my select I always have to impose this condition in the query, is there any way to do the filter implicitly? remembering that it is EF 6. 

var consulta = this.Contexto.Set<ClienteIdRaiz>().AsQueryable();
var totalRegistros = 0;

consulta = consulta.Where(x => !x.Excluido);
    
asked by anonymous 18.12.2017 / 19:09

1 answer

2

The Entity Framework 6 does not have the ability to do nuget :

has the addition of features about Entity Framework 6 and one of them is to provide a global filter on your SQL implicitly.

After installing the two packages and configuring your class, add a line inside the construtor of the class that inherits from DbContext . One scenario would be to recover all people with the Ativo = 1 , example field: 

public DatabaseContext()
        :base(ConnStr)
{
    Database.SetInitializer<DatabaseContext>(null);
    QueryFilterManager.Filter<People>(x => x.Where(a => a.Active == true));
}

or

Call the extension method Filter<> , example : 

public DatabaseContext()
            :base(ConnStr)
{
    Database.SetInitializer<DatabaseContext>(null);            
    this.Filter<People>(x => x.Where(a => a.Active));
}

In addition to the filters this is standard throughout the application, by name already says Global Query Filter . If any time in the application requires that this filter is not called, use the AsNoFilter() , example method: 

db.People.AsNoFilter().ToList();

The filter will not be added in SQL .

Minimum complete example: 

using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity;
using System.Linq;
using Z.EntityFramework.Plus;

namespace ConsoleApp41.Models
{
    public class People
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public bool Active { get; set; }
    }

    public class DatabaseContext: DbContext
    {
        protected const string ConnStr = "Connect_Strings";
        public DatabaseContext()
            :base(ConnStr)
        {
            Database.SetInitializer<DatabaseContext>(null);
            QueryFilterManager.Filter<People>(x => x.Where(a => a.Active == true));
        }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<People>()
                .ToTable("People");

            modelBuilder.Entity<People>()
                .HasKey(X => X.Id)
                .Property(x => x.Id)
                .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
                .IsRequired();

            modelBuilder.Entity<People>()
                .Property(x => x.Name)
                .HasMaxLength(50)
                .IsRequired();

            modelBuilder.Entity<People>()
                .Property(x => x.Active)
                .IsRequired();

        }

        public DbSet<People> People { get; set; }
    }
}

The documentation has a variety of filters , but , on your doubt what is in the answer is the ideal for your development.

This feature is not present in the Entity Framework 6 , but Entity Framework Core already exists such a resource with the name of Global Query Filters , how to configure?

In the OnModelCreating method, add a line as an example below: 

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<People>().HasQueryFilter(p => p.Active);
    //
}

has the same effect as the example of the package installed in the 6 version and also can disable using the IgnoreQueryFilters() 

var result  = db.People.IgnoreQueryFilters().ToList();

18.12.2017 / 20:04
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