10月7日学习进度

一.所花时间

半小时

二.代码量

40行

三.博客量

1篇

四.了解到的知识点

安卓连接SQLite数据库进行增删改查

package com.example.myapplication;

import com.example.myapplication.enity.User;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.CheckBox;
import android.widget.EditText;


import androidx.appcompat.app.AppCompatActivity;

import com.example.myapplication.database.UserDBHelper;
import com.example.myapplication.util.ToastUtil;

import java.util.List;

public class SQLiteHelperActivity extends AppCompatActivity implements View.OnClickListener {

    private EditText et_name;
    private EditText et_age;
    private EditText et_height;
    private EditText et_weight;
    private CheckBox ck_married;
    private UserDBHelper mHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_sqlite_helper);

        et_name = findViewById(R.id.et_name);
        et_age = findViewById(R.id.et_age);
        et_height = findViewById(R.id.et_height);
        et_weight = findViewById(R.id.et_weight);
        ck_married = findViewById(R.id.ck_married);

        findViewById(R.id.btn_save).setOnClickListener(this);
        findViewById(R.id.btn_delete).setOnClickListener(this);
        findViewById(R.id.btn_update).setOnClickListener(this);
        findViewById(R.id.btn_query).setOnClickListener(this);
    }


    @Override
    public  void onStart(){
        super.onStart();
        mHelper = UserDBHelper.getInstance(this);
        mHelper.openWriteLink();
        mHelper.openReadLink();
    }

    @Override
    protected void onStop() {
        super.onStop();
        mHelper.closeLink();
    }

    @Override
    public void onClick(View v) {

        String name = et_name.getText().toString();
        String age = et_age.getText().toString();
        String height = et_height.getText().toString();
        String weight = et_weight.getText().toString();
        User user = null;

        if(v.getId()==R.id.btn_save) {

            user = new User(name,
                    Integer.parseInt(age),Long.parseLong(height),
                    Float.parseFloat(weight),ck_married.isChecked());
            if(mHelper.insert(user)>0){
                ToastUtil.show(this,"添加成功");
            }

        }else if(v.getId()==R.id.btn_delete){
            if (mHelper.deleteByName(name) > 0) {
                ToastUtil.show(this, "删除成功");
            }
        }else if(v.getId()==R.id.btn_update){
            user = new User(name,
                    Integer.parseInt(age),
                    Long.parseLong(height),
                    Float.parseFloat(weight),
                    ck_married.isChecked());
            if (mHelper.update(user) > 0) {
                ToastUtil.show(this, "修改成功");
            }

        }else if(v.getId()==R.id.btn_query){
            List<User> list = mHelper.queryAll();
            //List<User> list = mHelper.queryByName(name);
            for (User u : list) {
                Log.d("ning", u.toString());
            }
        }else {

        }


    }



}