java - Google App Engine 数据存储区-主键

Question

我已在 Google App Engine 数据存储区中创建了一个表。它包含以下FIELDS(GROUPNAME,GROUPID,GROUPDESC)。如何将 GROUPID 设置为主键？

我的代码如下:

@Entity

@Table(name="group" , schema="PUBLIC")

public class Creategroup {

    @Basic

    private String groupname;

     @Basic   

    private  String groupid;

    @Basic

    private String groupdesc;



 public void setGroupname(String groupname) {

  this.groupname = groupname;

 }

 public String getGroupname() {

  return groupname;

 }

 public void setGroupid(String groupid) {

  this.groupid = groupid;

 }

 public String getGroupid() {

  return groupid;

 }

 public void setGroupdesc(String groupdesc) {

  this.groupdesc = groupdesc;

 }

 public String getGroupdesc() {

  return groupdesc;

 }

 public Creategroup(String groupname, String groupid, String groupdesc
   ) {

  // TODO Auto-generated constructor stub
    this.groupname = groupname;

    this.groupid = groupid;

    this.groupdesc = groupdesc;


 }

}

Answer 1

您可以使用 @PrimaryKey 注释设置主键，如 Defining Data Classes 中所述。文档。