咱们已经知道了在OnModelCreating()方法中能够经过FluentApi对全部的实体类进行配置,然而当实体类不少时,咱们把全部的配置都放在OnModelCreating()方法中很难维护。EF6容许咱们给每个实体添加一个单独的配置类,经过这个配置类来对相应的实体进行配置。ide
以配置Student实体类为例,咱们在OnModelCreating()方法中配置Student实体,代码以下:ui
public class SchoolDBContext: DbContext { public SchoolDBContext(): base() { } public DbSet<Student> Students { get; set; } protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity<Student>().ToTable("StudentInfo"); modelBuilder.Entity<Student>().HasKey<int>(s => s.StudentKey); modelBuilder.Entity<Student>() .Property(p => p.DateOfBirth) .HasColumnName("Birthday") .HasColumnOrder(3) .HasColumnType("datetime2"); modelBuilder.Entity<Student>() .Property(p => p.StudentName) .HasMaxLength(50); modelBuilder.Entity<Student>() .Property(p => p.StudentName) .IsConcurrencyToken(); modelBuilder.Entity<Student>() .HasMany<Course>(s => s.Courses) .WithMany(c => c.Students) .Map(cs => { cs.MapLeftKey("StudentId"); cs.MapRightKey("CourseId"); cs.ToTable("StudentCourse"); }); } }
咱们能够将每一个实体类的配置放在一个对应的的配置类,(如Studnet的实体配置在StudentEntityConfiguratinos配置类中),若是程序中有不少实体类,采用单独配置的方式能够很好的提升配置的可维护性和可读性。this
步骤以下:spa
步骤①:建立一个StudentEntityConfiguratinos类,这个类继承 EntityTypeConfiguration<TEntity> ,代码以下:code
public class StudentEntityConfiguration: EntityTypeConfiguration<Student> { public StudentEntityConfiguration() { this.ToTable("StudentInfo"); this.HasKey<int>(s => s.StudentKey); this.Property(p => p.DateOfBirth) .HasColumnName("DoB") .HasColumnOrder(3) .HasColumnType("datetime2"); this.Property(p => p.StudentName) .HasMaxLength(50); this.Property(p => p.StudentName) .IsConcurrencyToken(); this.HasMany<Course>(s => s.Courses) .WithMany(c => c.Students) .Map(cs => { cs.MapLeftKey("StudentId"); cs.MapRightKey("CourseId"); cs.ToTable("StudentCourse"); }); } }
步骤②: 在OnModelCreating()方法中使用上边的配置类:blog
public class SchoolDBContext: DbContext { public SchoolDBContext(): base() { } public DbSet<Student> Students { get; set; } protected override void OnModelCreating(DbModelBuilder modelBuilder) { // 添加Student实体的配置 modelBuilder.Configurations.Add(new StudentEntityConfiguration()); } }