Android学习（十） SQLite 基于内置函数的操作方式

main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    tools:context=".MainActivity" >



    <Button

        android:id="@+id/button1"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="插入数据" />



    <Button

        android:id="@+id/button2"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="读取数据" />



    <Button

        android:id="@+id/button3"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="修改数据" />



    <Button

        android:id="@+id/button4"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="删除数据" />



</LinearLayout>

 

main.java

package com.example.sqlitedemo2;



import android.app.Activity;

import android.content.ContentValues;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import android.os.Bundle;

import android.util.Log;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.Toast;



public class MainActivity extends Activity {



    Button btn1;

    Button btn2;

    Button btn3;

    Button btn4;

    SQLiteDatabase db;



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);



        db = openOrCreateDatabase("stu.db", MODE_PRIVATE, null);



        db.execSQL("create table if not exists tb_user(id integer primary key autoincrement,name text not null,age integer not null,sex text not null)");



        btn1 = (Button) findViewById(R.id.button1);

        btn2 = (Button) findViewById(R.id.button2);

        btn3 = (Button) findViewById(R.id.button3);

        btn4 = (Button) findViewById(R.id.button4);



        btn1.setOnClickListener(new OnClickListener() {



            @Override

            public void onClick(View v) {

                ContentValues values = new ContentValues();

                values.put("name", "李四");

                values.put("age", 20);

                values.put("sex", "女");                

                db.insert("tb_user", null, values);

                values.clear();

                

                values.put("name", "王五");

                values.put("age", 22);

                values.put("sex", "男");                

                db.insert("tb_user", null, values);

                Toast.makeText(MainActivity.this, "添加成功", 1).show();

            }

        });



        btn2.setOnClickListener(new OnClickListener() {



            @Override

            public void onClick(View v) {

                Cursor cur = db.query("tb_user", new String[]{"name","age","sex"}, null, null, null, null, null);

                while(cur.moveToNext()){

                    String name = cur.getString(cur.getColumnIndex("name"));

                    int age = cur.getInt(cur.getColumnIndex("age"));

                    String sex = cur.getString(cur.getColumnIndex("sex"));

                    

                    Log.i("stuinfo", name + "," + age + "," + sex);

                }

                cur.close();

            }

            

        });

        

        

        btn3.setOnClickListener(new OnClickListener() {

            

            @Override

            public void onClick(View v) {

                //修改数据

                ContentValues values = new ContentValues();

                values.put("name", "张三丰");

                int result = db.update("tb_user", values, "id=?", new String[]{"1"});

                if(result > 0)

                    Toast.makeText(MainActivity.this, "修改成功", 1).show();

                else

                    Toast.makeText(MainActivity.this, "修改失败", 1).show();

            }

        });

        

        btn4.setOnClickListener(new OnClickListener() {

            

            @Override

            public void onClick(View v) {

                //删除数据

                int result = db.delete("tb_user", "id=?", new String[]{"1"});

                if(result > 0)

                    Toast.makeText(MainActivity.this, "删除成功", 1).show();

                else

                    Toast.makeText(MainActivity.this, "删除失败", 1).show();

            }

        });

    }



}