006_01SQLite_demo

package com.example.sqlitedemo;

import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

public class MainActivity extends Activity {
    SQLiteDatabase db = null;
    public static String TAG = "sqlitedemo";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        db = SQLiteDatabase.openOrCreateDatabase(getFilesDir()+"/userinfo.db", null);
        
        createTable(db);
    }
    public void insert(View v){
        insert(db);
    }
    public void delete(View v){
        delete(db);
    }
    public void update(View v){
        update(db);
    }
    public void query(View v){
        query(db);
    }
    
    private void update(SQLiteDatabase db){
        String update = "update user set password=? where id = ?";
        Object[] args = {"99999999", 5};
        db.execSQL(update, args);
    }
    
    private void delete(SQLiteDatabase db){
        String delete = "delete from user where id =?";
        Object[] args = {5};
        db.execSQL(delete, args);
    }
    
    private void query(SQLiteDatabase db){
        String query = "select * from user";
        Cursor resultSet = db.rawQuery(query, null);
        
        int row = resultSet.getCount();
        Log.i(TAG, row+"");
        
        while(resultSet.moveToNext()){
            int id = resultSet.getInt(0);
            String username = resultSet.getString(1);
            String password = resultSet.getString(2);
            Log.i(TAG, id + "," +username+ "," + password);
                    
        }

    }
    private void insert(SQLiteDatabase db){
        String insert = "insert into user values(?,?,?)";
        Object[] args = {5, "user5", "55555555"};
        db.execSQL(insert, args);
    }
    
    private void createTable(SQLiteDatabase db){
        String createtable = "create table user(id int, name varchar(20),password char(8))";
        db.execSQL(createtable);
    }


}

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.sqlitedemo.MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="insert"
        android:text="insert" />

    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="delete"
        android:text="delete" />

    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="update"
        android:text="update" />

    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="query"
        android:text="query" />

</LinearLayout>

增删改查界面：