java - 多对多 ormlite 问题

Question

我使用的数据库是 ormlite。这是一个用于存储项目、开发人员的数据库，另一个是用于项目和开发人员之间的多对多关系的数据库。但是当我想使用开发人员的名字作为例子时，它们是空的。提前致谢。

DatabaseHelper helper = DatabaseManager.getDatabaseHelper(this);
        DeveloperEntity developerEntity = new DeveloperEntity("ahmad","java",null);
        try {
            helper.getDeveloperDao().createOrUpdate(developerEntity);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        ProjectEntity projectEntity = new ProjectEntity("acopal",null);
        try {
            helper.getProjectDao().createOrUpdate(projectEntity);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        DeveloperProjectEntity developerProjectEntity = new DeveloperProjectEntity(developerEntity,projectEntity);
        try {
            helper.getDeveloperProjectDao().createOrUpdate(developerProjectEntity);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        try {
             developerProjectEntityList = DatabaseManager.getDatabaseHelper(this)
                    .getDeveloperProjectDao().
                            queryForAll();
        } catch (SQLException e) {
            e.printStackTrace();
        }

package com.example.acopaldatabase.database.model;

import com.j256.ormlite.field.DatabaseField;
import com.j256.ormlite.table.DatabaseTable;

import java.io.Serializable;

@DatabaseTable(tableName = "developer_project")
public class DeveloperProjectEntity implements Serializable {


    @DatabaseField(generatedId = true)
    private int id;

    @DatabaseField(foreign = true,columnName = "developer_id", canBeNull = false)
    private DeveloperEntity developer;

    @DatabaseField(foreign = true,columnName = "project_id", canBeNull = false)
    private ProjectEntity project;


    public DeveloperProjectEntity() {
    }


    public DeveloperProjectEntity(DeveloperEntity developer, ProjectEntity project) {
        this.developer = developer;
        this.project = project;
    }




    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }


    public DeveloperEntity getDeveloper() {
        return developer;
    }
    public void setDeveloper(DeveloperEntity developer) {
        this.developer = developer;
    }



    public ProjectEntity getProject() {
        return project;
    }
    public void setProject(ProjectEntity project) {
        this.project = project;
    }
}

查看调试结果：图片请打开

调试结果

标签： javaandroiddatabaseormlite