Question

我在我的C＃应用程序中使用FluentNhibernate我想知道如何连接三个没有定义外键的表。让我们假设我有以下表结构，

学生[StudentID，Name1，Name2，ClassID]

班级[ClassID，姓名，学校ID]

学校[SchoolID，SchoolName]

我需要加入以上三个表格

SELECT a.Name1,a.Name2,b.Name,c.SchoolName FROM Student a, Class b, School c WHERE a.ClassID = b.ClassID AND b.SchoolID = c.SchoolID

我有以下ORM的类结构

public class Student
{
        public virtual int      StudentID { get; set; }
        public virtual string   Name1 { get; set; }
        public virtual string   Name2 { get; set; }
        public virtual int      ClassID  { get; set; }
 }



 public class StudentMap : ClassMap<Student>
    {
        public StudentMap()
        {
            Id(x => x.StudentID ).Column("student_id");
            Map(x => x.Name1 ).Column("name_1");
            Map(x => x.Name1 ).Column("name_2");
            Map(x => x.ClassID).Column("class_Id");
            Table("student");
        }
    }





public class Classt
{
        public virtual int      ClassID { get; set; }
        public virtual string   Name { get; set; }
        public virtual int      SchoolID  { get; set; }
 }



 public class ClassMap : ClassMap<Class>
    {
        public ClassMap ()
        {
            Id(x => x.ClassID ).Column("class_id");
            Map(x => x.Name ).Column("name");
            Map(x => x.SchoolID).Column("school_Id");
            Table("class");
        }
    }




public class School
{
        public virtual int      SchooID { get; set; }
        public virtual string   Name { get; set; }
 }



 public class SchoolMap : ClassMap<School>
    {
        public SchoolMap ()
        {
            Id(x => x.ClassID ).Column("class_id");
            Map(x => x.Name ).Column("name");
            Table("school");
        }
    }

Answer 1

你应该这样做;

public class Student
{
        public virtual int      StudentID { get; set; }
        public virtual string   Name1 { get; set; }
        public virtual string   Name2 { get; set; }
        public virtual List<Class> ClassList  { get; set; }
}

public class StudentMap : ClassMap<Student>
{
    public StudentMap()
    {
        Id(x => x.StudentID ).Column("student_id");
        Map(x => x.Name1 ).Column("name_1");
        Map(x => x.Name1 ).Column("name_2");
        HasMany(x => x.Class).KeyColumn("ClassId")
        Table("student");
    }
}

public class Class
{
        public virtual int      ClassID { get; set; }
        public virtual string   Name { get; set; }
        public virtual IList<Student> StudentList { get; set; }
        public virtual School School  { get; set; }
}

public class ClassMap : ClassMap<Class>
{
    public ClassMap ()
    {
        Id(x => x.ClassID ).Column("class_id");
        Map(x => x.Name ).Column("name");
        HasMany(x => x.Student).KeyColumn("StudentId")
        References(x => x.School)
        Table("class");
    }
}

public class School
{
    public virtual int      SchoolID { get; set; }
    public virtual string   Name { get; set; }
    public virtual IList<Class> ClassList { get; set; }
}

public class SchoolMap : ClassMap<School>
{
    public SchoolMap ()
    {
        Id(x => x.SchoolID ).Column("SchoolId");
        Map(x => x.Name ).Column("name");
        HasMany(x => x.ClassList).KeyColumn("ClassId")
        Table("school");
    }
}

如何使用FluentNhibernate连接三个表

1 个答案: