messengerapi/code/MessengerApi.Db.Sql/MessengerSqlDbContext.cs

using MessengerApi.Db.Entities;
using Microsoft.EntityFrameworkCore;

namespace MessengerApi.Db.Sql
{
    public class MessengerSqlDbContext : MessengerDbContext
    {
        private readonly string connectionString;

        public MessengerSqlDbContext(string connectionString)
        {
            this.connectionString = connectionString;
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            base.OnConfiguring(optionsBuilder);
            optionsBuilder.UseSqlServer(this.connectionString);
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            // https://stackoverflow.com/questions/26464357/what-is-the-purpose-of-non-unique-indexes-in-a-database
            // https://stackoverflow.com/questions/40767980/generate-a-composite-unique-constraint-index-in-ef-core
            // https://www.geeksforgeeks.org/difference-between-clustered-and-non-clustered-index/
            modelBuilder.Entity<Message>().HasIndex(e => new { e.ToId, e.IsDelivered }).IsUnique(false).IsClustered(false);
        }
    }
}