07,数据库的常用操作

0增加一条数据

//返回插入数据实体的id
long insert = studentDao.insert(new Student() {
    {
        this.setHobby("写代码");
        this.setName("王小明");
        this.setNumber(1);
        this.setAge(22);
    }
});
if (insert > 0) {
        DemonstrateUtil.showToastResult(this, "成功,实体id" + insert);
} else {
    DemonstrateUtil.showToastResult(this, "失败,实体id" + insert);
}

1删除一条数据

studentDao.deleteByKey(1l);

2修改一条数据

studentDao
  .update(new Student() {
            {
                setNumber(1);
                setName("王小明");
                setId(1l);
                setHobby("吃饭睡觉敲码");
            }
   });
DemonstrateUtil.showToastResult(this, "数据修改!");

3查询一条数据

Student student 
    = studentDao.load(1l);
if (null != student) {
            tvShow.setText(student.toString());
} else {
            tvShow.setText("查询的数据不存在!!");
            DemonstrateUtil
.showToastResult(MyApplication.getInstance(), "数据不存在哦!!");
}

4增加List集合数据

studentDao
.insertInTx(new ArrayList() {
      {
                for (int i = 1; i <= 5; i++) {
                    int num = i + 1;
                    num++;
                    add(new Student(null, "张非" + i, "吃饭" + i, num, 20));
       }
                add(new Student(null, "李四", "吃饭", 10, 15));
                add(new Student(null, "李四", "睡觉", 11, 16));
                add(new Student(null, "李四", "敲码", 12, 17));
                add(new Student(null, "李四", "爱说话", 13, 18));
}
});

5查询所有的数据

List studentList 
= studentDao.queryBuilder().list();
tvShow.setText(studentList.toString());
for (Student student : studentList) {            DemonstrateUtil
.showLogResult(student.toString());
}

6查询指定字段的数据

List students 
= studentDao
.queryBuilder()
.where(StudentDao.Properties.Name.eq("张非3"))
.list();
tvShow.setText(students.toString());
for (Student student : students) {
DemonstrateUtil
.showLogResult(student.toString());
}

7查询指定字段的数据降序排列

List students 
= studentDao
                .queryBuilder()
                .where(StudentDao.Properties.Name.eq("李四"))
                .orderDesc(StudentDao.Properties.Age)
                .list();
        tvShow.setText(students.toString());
for (Student student : students) {
//DemonstrateUtil.showLogResult(student.toString());
 }

8查询指定字段的数据升序排列

List students 
= studentDao
                .queryBuilder()
                .where(StudentDao.Properties.Name.eq("李四"))
                .orderAsc(StudentDao.Properties.Age)
                .list();
tvShow.setText(students.toString());
for (Student stu : students) {
  DemonstrateUtil.showLogResult(stu.toString());
}

9组合查询数据

List students 
= studentDao
                .queryBuilder()
                .where(StudentDao.Properties.Name.eq("李四"), StudentDao.Properties.Age.le(17))
                .list();
tvShow.setText(students.toString());
for (Student stu : students) {
     DemonstrateUtil.showLogResult(stu.toString());
}

10查询所有的数据,只取指定条数

List students 
= studentDao
                .queryBuilder()
                .limit(3)
                .list();
tvShow.setText(students.toString());
for (Student student : students) {
            DemonstrateUtil
.showLogResult(student.toString());
}

11查询所有,取指定条数,跳过某条

List students 
= studentDao
                .queryBuilder()
                .limit(3)
                .offset(2)
                .list();
tvShow.setText(students.toString());
for (Student student : students) {
      DemonstrateUtil
.showLogResult(student.toString());
}

12查询数据总条数

 /*tvShow
.setText("总条数:" + studentDao.queryBuilder()
                .list().size());*/
tvShow.setText("总条数:" + studentDao.count());

13修改指定字段的数据

Student student
 = studentDao.
                queryBuilder()
                .where(StudentDao.Properties.Name.eq("张非1"))
                .unique();
if (null != student) {
            student.setName("张三");
            studentDao.update(student);
            DemonstrateUtil.showToastResult(this, "修改成功!");
Student student1 
= studentDao
                    .queryBuilder()
                    .where(StudentDao.Properties.Name.eq("张三"))
                    .unique();
            DemonstrateUtil
.showLogResult(student1.toString());
 } else {
            DemonstrateUtil
.showToastResult(this, "要修改的数据不存在!!");
}

14删除指定数据方式1

studentDao
                .queryBuilder()
                .where(StudentDao.Properties.Name.eq("张非2"))
                .buildDelete()
                .executeDeleteWithoutDetachingEntities();
DemonstrateUtil.showLogResult("删除成功!");

15删除指定数据方式2

Student student 
= studentDao.
                queryBuilder()
                .where(StudentDao.Properties.Name.eq("张非4"))
                .unique();
 studentDao.delete(student);
 DemonstrateUtil.showLogResult("删除,张非4");

16删除全部数据

//删除全部数据!
studentDao.deleteAll();