Database improvement

1.  Separate configuration files
2.  Remove commented code
3.  Improve entity configurations (constraints, indexes, relationships)

Data/AppDbContext.cs

@@ -1,7 +1,6 @@
 using System.Reflection;
 using Core.Entities;
 using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Metadata.Builders;
 
 namespace Data
 {
@@ -24,64 +23,5 @@ namespace Data
         {
             modelBuilder.ApplyConfigurationsFromAssembly(Assembly.GetExecutingAssembly());
         }
-
-        //protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
-        //{
-        //    var dbPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "ChapterOrganizer.db");
-        //    optionsBuilder.UseSqlite($"Data Source={dbPath}");
-        //}
-    }
-
-    public class EventDefinitionConfiguration : IEntityTypeConfiguration<EventDefinition>
-    {
-        public void Configure(EntityTypeBuilder<EventDefinition> builder)
-        {
-            builder.HasKey(u => u.Id);
-
-            builder.HasIndex(u => u.Name);
-            builder.Property(u => u.Name).HasMaxLength(128);
-
-            //builder.HasMany(u => u.Roles)
-            //    .WithOne()
-            //    .HasForeignKey(r => r.Id)
-            //    .OnDelete(DeleteBehavior.Restrict);
-        }
-    }
-
-    public class StudentConfiguration : IEntityTypeConfiguration<Student>
-    {
-        public void Configure(EntityTypeBuilder<Student> builder)
-        {
-            builder.HasKey(u => u.Id);
-            //builder.Property(s => s.Grade);
-
-            builder
-                .HasMany(e => e.RankedEvents)
-                .WithMany()
-                .UsingEntity<StudentEventRanking>()
-                .HasOne<EventDefinition>(e => e.EventDefinition);
-        }
-    }
-
-    public class TeamConfiguration : IEntityTypeConfiguration<Team>
-    {
-        public void Configure(EntityTypeBuilder<Team> builder)
-        {
-            builder.HasKey(u => u.Id);
-
-            builder.HasMany(e => e.Students)
-                .WithMany(e => e.Teams);
-
-            builder.HasOne(e => e.Captain);
-
-        }
-    }
-    public class StudentEventRankingConfiguration : IEntityTypeConfiguration<StudentEventRanking>
-    {
-        public void Configure(EntityTypeBuilder<StudentEventRanking> builder)
-        {
-            //builder.HasKey(u => u.EventDefinitionId);
-            //builder.HasKey(u => u.StudentId);
-        }
     }
 }