007_01SQLiteTransaction

package com.example.sqlitetransaction;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class MydbOpenHelper extends SQLiteOpenHelper {

    //
    public MydbOpenHelper(Context context, String name, CursorFactory factory,
            int version) {
        super(context, name, factory, version);
        // TODO Auto-generated constructor stub
    }

    
    //oncreate函数当数据库第一次被创建的时候会调用
    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        String createtable = "create table user(id int, name varchar(20), money int);";
        db.execSQL(createtable);
        System.out.println("MydbOpenHelper.onCreate()");
    }

    
    //onUpgrade当你的数据库版本升级的时候会调用
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        //更改数据库的表结构
        //  user(id,name,password)  user(id,name,password,gender)
        //
        //  db.execSQL(""); 
        Log.i("MydbOpenHelper", "oldervserion"+oldVersion+"newversion"+newVersion);
        System.out.println("MydbOpenHelper.onUpgrade()");

    }

}

package com.example.sqlitetransaction;

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.Menu;
import android.view.MenuItem;

public class MainActivity extends Activity {
    SQLiteDatabase db;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        MydbOpenHelper helper = new MydbOpenHelper(this, "count.db", null,1);
        db = helper.getReadableDatabase();
        
        //insert();
        try {
            update();        
            query();
        } 
        finally{
            db.close();            
        }
        
        }
    private void update(){
        db.beginTransaction();
        try{
            ContentValues cv = new ContentValues();
            cv.put("money", 7000);
            db.update("user", cv, "id=1", null);
            
            //int b = 1/0;
            
            cv.clear();
            cv.put("money", 11000);
            db.update("user", cv, "id=2", null);
            db.setTransactionSuccessful();
        }catch(Exception e){
            
        }finally{
            db.endTransaction();
        }

    }
    private void query(){
        Cursor c = db.rawQuery("select * from user", null);
        
        while(c.moveToNext()){
            int id = c.getInt(c.getColumnIndex("id"));
            String username = c.getString(c.getColumnIndex("name"));
            String money = c.getString(c.getColumnIndex("money"));
            Log.i("sqlitetransaction", id+","+username+","+money);
        }
    }
    private void insert(){
        ContentValues cv = new ContentValues();
        cv.put("id", 1);
        cv.put("name", "user1");
        cv.put("money", 8000);
        db.insert("user", null, cv);
        cv.clear();
        
        cv.put("id", 2);
        cv.put("name", "user2");
        cv.put("money", 10000);
        db.insert("user", null, cv);
        cv.clear();
    }
}