How to intercept database operation in EF core 3?

Question

How do I intercept before the database operation like select/delete/insert/update using EF core 3 in PostgreSQL?

In the new feature of EF core 3.0 https://docs.microsoft.com/en-gb/ef/core/what-is-new/ef-core-3.0/#interception-of-database-operations, DbCommandInterceptor is used for that. However, I couldn't find this class nor the AddInterceptors.

Do I need to install new nuget or using specific namespace?

Answer 1

I have found what I need and successfully implemented.

using System.Data.Common;
using Microsoft.EntityFrameworkCore.Diagnostics;

public class RowLevelSecurityInterceptor : DbCommandInterceptor
{
  public override InterceptionResult<DbDataReader> ReaderExecuting(
    DbCommand command,
    CommandEventData eventData,
    InterceptionResult<DbDataReader> result)
  {
    // command.CommandText += " OPTION (OPTIMIZE FOR UNKNOWN)";
    return result;
  }
}

public class MyDbContext : DbContext
{
  // previous codes
  protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
  {

    optionsBuilder
      .UseNpgsql(GetConnectionString())
      .AddInterceptors(new RowLevelSecurityInterceptor());
    }
  }
}