[移动开发]Android Studio 使用SQLite进行数据的增删改查

网课指路 B站大神:（学完必会）Android studio基础，从入门到精通，学完小白也能会_哔哩哔哩_bilibili

package com.example.databasetest;

import androidx.appcompat.app.AppCompatActivity;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {
    private MyDatabaseHelper dbHelper;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn = (Button)(findViewById(R.id.btn));
        Button btn2 = (Button)(findViewById(R.id.btn2));
        Button btn3= (Button)(findViewById(R.id.btn3));
        Button btn4= (Button)(findViewById(R.id.btn4));
        Button btn5= (Button)(findViewById(R.id.btn5));
        dbHelper = new MyDatabaseHelper(this,"zhangke.dp",null,1);
        btn3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SQLiteDatabase db = dbHelper.getWritableDatabase();//读取
                ContentValues values = new ContentValues();//开始组装第一条记录
                values.put("name","ZK");
                db.update("people",values,"name = ?",new String[]{"zhangke"});
            }
        });
        btn5.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SQLiteDatabase db = dbHelper.getWritableDatabase();//读取
                Cursor cursor = db.query("people",null,null,null,null,null,null);
                if(cursor.moveToFirst()){
                    do{
                        String name = cursor.getString(cursor.getColumnIndex("name"));
                        int id = cursor.getInt(cursor.getColumnIndex("id"));
                        Log.d("MainActivity","name"+name);
                        Log.d("MainActivity","id"+id);
                    }while (cursor.moveToNext());
                }
            }
        });
        btn4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SQLiteDatabase db = dbHelper.getWritableDatabase();//读取
                db.delete("people","age > ?",new String[]{"23"});
            }
        });
        btn2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SQLiteDatabase db = dbHelper.getWritableDatabase();//读取
                ContentValues values = new ContentValues();//开始组装第一条记录
                values.put("name","zhangke");
                values.put("sex","male");
                values.put("age",25);
                values.put("weight",74.7);
                db.insert("people",null,values);//输入第一条数据
                values.clear();
                values.put("name","TJW");
                values.put("sex","female");
                values.put("age",22);
                values.put("weight",48);
                db.insert("people",null,values);//输入第二条数据
                values.clear();
            }
        });
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dbHelper.getWritableDatabase();
            }//创建
        });
    }
}