你如何在 Hibernate ActiveRecord 中进行连接？

Question

我如何进行一个连接，它会返回类似于 -

SELECT * FROM Project LEFT JOIN ProjectRegion ON ProjectRegion.id = Project.projectRegion

我当前使用的语法 -

  Project[] projects = Project.FindAll();

我的表是使用 ActiveRecord/hibernate 设置的，如下所示 -

    [ActiveRecord]
    public class ProjectRegion : ActiveRecordBase<ProjectRegion>
    {
        private int id;
        private String title;

        public ProjectRegion()
        {
        }

        [PrimaryKey]
        public int Id
        {
            get { return id; }
            set { id = value; }
        }

        [Property]
        public String Title
        {
            get { return title; }
            set { title = value; }
        }
    }


    [ActiveRecord]
    public class Project : ActiveRecordBase<Project>
    {
        private int id;
        private String projectNumber;
        private String projectRegion;

        public Project()
        {
        }

        [PrimaryKey]
        public int Id
        {
            get { return id; }
            set { id = value; }
        }

        [Property]
        public String ProjectInternalCode
        {
            get { return projectNumber; }
            set { projectNumber = value; }
        }

        [Property]
        public String ProjectRegion
        {
            get { return projectRegion; }
            set { projectRegion = value; }
        }
...

Answer 1

如果您将 Project 类中的 ProjectRegion 属性声明为 ProjectRegion 类型而不是字符串类型，则当 NHibernate 获取 Project 时，它将自动连接（根据获取策略）ProjectRegion 表。