compile 'org.litepal.android:core:1.5.1'

<?xml version="1.0" encoding="UTF-8" ?>
<litepal><!--数据库的名字--><dbname value="School"></dbname><!--数据库的版本好--><version value="1"></version><!--表--><list><mapping class="com.example.dell.testlitepal.Student"></mapping></list>
</litepal>

import org.litepal.crud.DataSupport;public class Student extends DataSupport {private int id;private String number;private String name;private int age;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getNumber() {return number;}public void setNumber(String number) {this.number = number;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}@Overridepublic String toString() {return "学生{" +"id=" + id +", 学会='" + number + '\'' +", 姓名='" + name + '\'' +", 年龄=" + age +'}';}
}

CREATE TABLE student (id integer primary key autoincrement,age integer, name text, number text);

Student student = new Student();
student.setNumber("1238409");
student.setName("小明");
student.setAge(21);
//必须使用save()才生效
student.save();

Student student1 = new Student();
//设置要更新的数据
student1.setAge(0);
student1.setName("111111");
//声明要设置的值是跟默认值冲突的列
student1.setToDefault("age");
//执行更新和说明条件
student1.updateAll("name = ?", "小明");

//表对应的类、条件、条件值
DataSupport.deleteAll(Student.class, "id > ?", "2");

//只需要传入表对应的JavaBean类，返回是集合
List<Student> students = DataSupport.findAll(Student.class);

//在find加上where，写入条件
List<Student> students1 = DataSupport.where("age = ?", "21").find(Student.class);

List<Student> students2 = new ArrayList<>();
//同普通的SQL操作差不多
Cursor cursor = DataSupport.findBySQL("select * from student where age = ? and id> ?", "21", "3");
if (cursor != null) {while (cursor.moveToNext()) {Student stu = new Student();stu.setId(cursor.getInt(cursor.getColumnIndex("id")));stu.setNumber(cursor.getString(cursor.getColumnIndex("number")));stu.setName(cursor.getString(cursor.getColumnIndex("name")));stu.setAge(cursor.getInt(cursor.getColumnIndex("age")));students2.add(stu);}cursor.close();
}

//获取第一条数据
Student firstStu = DataSupport.findFirst(Student.class);
//获取最后一条数据
Student lastStu = DataSupport.findLast(Student.class);
//要查询某几列
List<Student> someLineStu = DataSupport.select("number", "name").find(Student.class);
//排序查询，("列名 规则") desc降序 asc升序
List<Student> orderStu = DataSupport.order("age desc").find(Student.class);
//只查前5条
List<Student> limitStu = DataSupport.limit(5).find(Student.class);
//查询结果的偏移量，跟limit搭配可以做分页使用,下面是从第3条开始，共查询5条
List<Student> offsetStu = DataSupport.limit(5).offset(2).find(Student.class);
//多种条件组合查询
List<Student> setStu = DataSupport.select("number", "name").where("id > ?", "3").order("age desc").limit(5).offset(4).find(Student.class);