GreenDao 3，阿里腾讯PDD等大厂安卓面试真题

return “Courses{” +

“courseId=” + courseId +

“, courseName=’” + courseName + ‘’’ +

“, teacherId=” + teacherId +

“, teacher=” + teacher +

‘}’;

}

Teachers teachers=new Teachers();

teachers.setTeacherId(31);

teachers.setTeacherName(“31 老师”);

teachers.setSex(“男”);

Teachers teachers1=new Teachers();

teachers1.setTeacherId(32);

teachers1.setTeacherName(“32 老师”);

teachers1.setSex(“男”);

Teachers teachers2=new Teachers();

teachers2.setTeacherId(33);

teachers2.setTeacherName(“33 老师”);

teachers2.setSex(“女”);

Courses courses=new Courses();

courses.setCourseId(1);

courses.setTeacherId(31);

courses.setCourseName(“语文”);

Courses courses1=new Courses();

courses1.setCourseId(2);

courses1.setTeacherId(32);

courses1.setCourseName(“英语”);

Courses courses2=new Courses();

courses2.setCourseId(3);

//courses2.setTeacherId(33);

courses2.setTeacher(teachers2);//设置Teachers 对象关联

courses2.setCourseName(“数学”);

//插入数据

GreenDaoUtils.getDaoSession().getTeachersDao().insertOrReplaceInTx(teachers,teachers1,teachers2);

GreenDaoUtils.getDaoSession().getCoursesDao().insertOrReplaceInTx(courses,courses1,courses2);

List teachers = GreenDaoUtils.getDaoSession().getTeachersDao().queryBuilder().build(
).list();

List courses = GreenDaoUtils.getDaoSession().getCoursesDao().queryBuilder().build().list();

Log.d(“LHW”,“teachers=”+teachers);

Log.d(“LHW”,“courses=”+courses);

@ToMany 一对多的使用

@Entity(nameInDb = “Students”)

public class Students {

@Id(autoincrement = true)

private long id;

@Property(nameInDb = “studentId”)

private long studentId;

@Property(nameInDb = “studentName”)

private String studentName;

@Property(nameInDb = “classes”)

private String classes;

@Property(nameInDb = “courseId”)//Courses表的主键id

private long courseId;

@ToMany(referencedJoinProperty =“courseId”)//一对多 一个学生多堂课

private List courses;

@Override

public String toString() {

return “Students{” +

“id=” + id +

“, studentId=” + studentId +

“, studentName=’” + studentName + ‘’’ +

“, classes=’” + classes + ‘’’ +

“, courseId=” + courseId +

“, courses=” + getCourses() +

‘}’;

}

Students students=new Students();

students.setId(1);

students.setStudentId(21);

students.setCourseId(1);

students.setStudentName(“21 学生”);

Students students1=new Students();

students1.setId(2);

students1.setStudentId(22);

students1.setCourseId(2);

students1.setStudentName(“22 学生”);

Students students2=new Students();

students2.setId(3);

students2.setStudentId(23);

students2.setCourseId(3);

students2.setStudentName(“23学生”);

GreenDaoUtils.getDaoSession().getStudentsDao().insertOrReplaceInTx(students,students1,students2);

List students = GreenDaoUtils.getDaoSession().getStudentsDao().queryBuilder().build().list();

Log.d(“LHW”,“students=”+students);

@ToMany @JoinEntity 多对多的使用

@Entity(nameInDb = “GradeJionTeacher”)

public class GradeJionTeacher {

@Id(autoincrement = true)

private long id;

@Property(nameInDb =“stuId”)

private long stuId;

@Property(nameInDb =“teaId”)

private long teaId;

@Entity(nameInDb = “Grade”)

public class Grade {

@Id(autoincrement = true)

private long id;

@Property(nameInDb = “gId”)

private long gId;

@Property(nameInDb = “gradeName”)

private String gradeName;

@Property(nameInDb = “gradeState”)

private String gradeState=“day day up”;

@ToMany //多对多 多个年纪对 多个老师

@JoinEntity(entity = GradeJionTeacher.class,sourceProperty = “stuId”,targetProperty = “teaId”)

private List teachersList;

@Override

public String toString() {

return “Grade{” +

“id=” + id +

“, gId=” + gId +

“, gradeName=’” + gradeName + ‘’’ +

“, gradeState=’” + gradeState + ‘’’ +

“, teachersList=” +getTeachersList()+//teachersList

‘}’;

}

@Entity(nameInDb = “Teachers”)

public class Teachers {

@Id(autoincrement = true)

@Property(nameInDb = “teacherId”)

private long teacherId;

@Property(nameInDb = “teacherName”)

private String teacherName;

@Property(nameInDb = “sex”)

private String sex;

@ToMany //多对多 多个老师 多个年纪

@JoinEntity(entity = GradeJionTeacher.class,sourceProperty = “teaId”,targetProperty = “stuId”)

private List grades;

@Override

public String toString() {

return “Teachers{” +

“teacherId=” + teacherId +

“, teacherName=’” + teacherName + ‘’’ +

“, sex=’” + sex + ‘’’ +

“, grades=” + grades +

‘}’;

}

Grade grade=new Grade();

grade.setId(41);

grade.setGId(41);

grade.setGradeName(“31 年纪”);

grade.setGradeState(“happy every day”);

Grade grade1=new Grade();

grade1.setId(42);

grade1.setGId(42);

grade1.setGradeName(“32 年纪”);

grade1.setGradeState("no happy ");

teacherName=’" + teacherName + ‘’’ +

“, sex=’” + sex + ‘’’ +

“, grades=” + grades +

‘}’;

}

Grade grade=new Grade();

grade.setId(41);

grade.setGId(41);

grade.setGradeName(“31 年纪”);

grade.setGradeState(“happy every day”);

Grade grade1=new Grade();

grade1.setId(42);

grade1.setGId(42);

grade1.setGradeName(“32 年纪”);

grade1.setGradeState("no happy ");