使用LitePal操作数据库

配置litepal环境

//1、导入项目依赖
implementation 'org.litepal.android:core:1.4.1'

//2、搭建实体类

package com.dds.huqin.pojo;

import org.litepal.crud.DataSupport;

public class User extends DataSupport {
    private int id;
    private String username;
    private String password;


    public int getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}


//3、配置litepal.xml文件，在/src/main目录下新建assets目录新建litepal.xml文件



    
    
    
        
    



//4、配置LitePalApplication
在AndroidManifest.xml中

 添加数据

 User user = new User();
        user.setUsername(et_reName.getText().toString());
        user.setPassword(et_rePwd.getText().toString());
        user.save();

更新数据

String name = up_name.getText().toString();
        String pwd = up_pwd.getText().toString();
        String username = getSharedPreferences("user",MODE_PRIVATE).getString("username","");
        String password = getSharedPreferences("user",MODE_PRIVATE).getString("password","");
        User user = new User();
        user.setUsername(name);
        user.setPassword(pwd);
        user.updateAll("username=? and password=?",username,password);

 删除数据

DataSupport.deleteAll(User.class,"username=?","name");

 查询数据

name = et_name.getText().toString();
        pwd = et_pwd.getText().toString();
        List users = DataSupport.where("username=? and password=?", name, pwd).find(User.class);
        try {
            if (name.equals(users.get(0).getUsername()) && pwd.equals(users.get(0).getPassword())) {
                Log.w("dds", users.get(0).getUsername());
                Toast.makeText(this, "登录成功", Toast.LENGTH_SHORT).show();
                Intent intent = new Intent(this, MainActivity.class);
                startActivity(intent);
            }
        } catch (Exception e) {
            e.printStackTrace();
            Toast.makeText(this, "用户名或密码错误", Toast.LENGTH_SHORT).show();
        }