标签:Name many builder EF public dotnetcore Student new Teacher
class Student
{
public int Id { get; set; }
public string Name { get; set; }
public List<Teacher> Teachers { get; } = new List<Teacher>();
}
class StudentConfig : IEntityTypeConfiguration<Student>
{
public void Configure(EntityTypeBuilder<Student> builder)
{
builder.ToTable("student");
builder.Property(e => e.Name).HasColumnType("nvarchar(50)").IsRequired();
}
}
class Teacher
{
public int Id { get; set; }
public string Name { get; set; }
public List<Student> Students { get; } = new List<Student>();
}
class TeacherConfig : IEntityTypeConfiguration<Teacher>
{
public void Configure(EntityTypeBuilder<Teacher> builder)
{
builder.ToTable("teacher");
builder.Property(e => e.Name).HasColumnType("nvarchar(50)").IsRequired();
// 使用hasMany()/withMany()+指定中间表
builder.HasMany(t => t.Students).WithMany(s => s.Teachers).UsingEntity(b => b.ToTable("teacher_student"));
}
}
class MyDbContext : DbContext
{
public DbSet<Teacher> Teachers { get; set; }
public DbSet<Student> Students { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
base.OnConfiguring(optionsBuilder);
ILoggerFactory loggerFactory = LoggerFactory.Create(builder => builder.AddConsole());
optionsBuilder.UseLoggerFactory(loggerFactory); // output sql script to log.
//optionsBuilder.LogTo(Console.WriteLine);
optionsBuilder.UseSqlServer("Server=.;Database=demo02;Trusted_Connection=True;MultipleActiveResultSets=True");
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.ApplyConfigurationsFromAssembly(this.GetType().Assembly);
}
}
class Program
{
static async Task Main(string[] args)
{
using (MyDbContext ctx = new MyDbContext())
{
await GetStudents(ctx);
}
}
private static Task GetStudents(MyDbContext ctx)
{
Student[] students = ctx.Students.Include(s => s.Teachers).Where(_ => true).ToArray();
foreach (Student s in students)
{
Console.WriteLine(s.Name);
foreach (Teacher t in s.Teachers)
{
Console.WriteLine($" {t.Name}");
}
}
return Task.CompletedTask;
}
private static async Task SaveStudentTeachers(MyDbContext ctx)
{
Student s1 = new Student { Name = "张三" };
Student s2 = new Student { Name = "李四" };
Student s3 = new Student { Name = "王五" };
Teacher t1 = new Teacher { Name = "tom" };
Teacher t2 = new Teacher { Name = "mike" };
Teacher t3 = new Teacher { Name = "jack" };
s1.Teachers.AddRange(new Teacher[] { t1, t2 });
s2.Teachers.AddRange(new Teacher[] { t2, t3 });
s3.Teachers.AddRange(new Teacher[] { t1, t2, t3 });
ctx.Students.AddRange(new Student[] { s1, s2, s3 });
await ctx.SaveChangesAsync();
}
}
标签:Name,many,builder,EF,public,dotnetcore,Student,new,Teacher 来源: https://www.cnblogs.com/mryux/p/15857340.html
本站声明: 1. iCode9 技术分享网(下文简称本站)提供的所有内容,仅供技术学习、探讨和分享; 2. 关于本站的所有留言、评论、转载及引用,纯属内容发起人的个人观点,与本站观点和立场无关; 3. 关于本站的所有言论和文字,纯属内容发起人的个人观点,与本站观点和立场无关; 4. 本站文章均是网友提供,不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属;如您发现该文章侵犯了您的权益,可联系我们第一时间进行删除; 5. 本站为非盈利性的个人网站,所有内容不会用来进行牟利,也不会利用任何形式的广告来间接获益,纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。