What is the use of `default` keyword in C#?
What is the use of default keyword in C#? Is it introduced in C# 3.0 ?
如何设置一个全球条件以隐藏被删除的元素
原标题：how to set a global condition to hide entites that are deleted
I want to set a condition on all entites to hide the ones that are deleted.
I could not find aa command in the Fluent Api to achieve this.
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity().HasQueryFilter(x => x.IsDeleted == false || x.IsDeleted ==null );
}
问题回答
For achieving this, you should first define a baseClass for all entities like this. (Nullable IsDeleted, depends on your scenario and business):
///
/// Base class for entities in the application.
///
public abstract class BaseEntity
{
// Properties
public virtual bool? IsDeleted { get; set; }
}
Then You should write a configuration for this base class like bellow to apply Global query filter.
///
/// Represents the abstract entity configuration for the
public class BaseEntityConfiguration : IEntityTypeConfiguration where TEntityType : BaseEntity
{
public virtual void Configure(EntityTypeBuilder builder)
{
// Retrieve all active and un deleted objects
builder.HasQueryFilter(p => p.IsDeleted != null && p.IsDeleted != false);
}
}
Then for configuring other entities you should follow like this. Assume that you have a billing entity, then configuration would be like this:
///
/// Represents the entity configuration for the
public class BillingConfiguration : BaseEntityConfiguration
{
public override void Configure(EntityTypeBuilder builder)
{
base.Configure(builder);
// Other configuration specially for Billing Entity
}
}
Hope this help you. any question, comment plz.
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