Android SQLite使用方法

程序內使用SQLite數據庫是通過SQLiteOpenHelper進行操作

1. 自己寫個類繼承SQLiteOpenHelper,重寫以下3個方法

public void onCreate(SQLiteDatabase db)

{//創建數據庫時的操作，如建表}

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)

{

//版本更新的操作

}

2. 通過SQLiteOpenHelper的getWritableDatabase()獲得一個SQLiteDatabase數據庫，以後的操作都是對SQLiteDatabase進行操作。

3. 對得到的SQLiteDatabase對象進行增，改，刪，查等操作。

代碼

package cx.myNote;

import android.content.ContentValues;

import android.content.Context;

import android.content.Intent;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;

//DBOptions for login

public class DBOptions {

private static final String DB_NAME = "notes.db";

private static final String DB_CREATE="create table logininf(name text,pwd text)";

public class DBHelper extends SQLiteOpenHelper

{

public DBHelper(Context context) {

super(context,DB_NAME, null, 1);

}

@Override

public void onCreate(SQLiteDatabase db) {

// TODO Auto-generated method stub

//建表

db.execSQL(DB_CREATE);

}

@Override

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

// TODO Auto-generated method stub

db.execSQL("drop table if exists logininf");

onCreate(db);

}

}

private Context context;

private SQLiteDatabase db;

private DBHelper dbHelper;

public DBOptions(Context context)

{

this.context = context;

dbHelper = new DBHelper(context);

db=dbHelper.getReadableDatabase();

}

//自己寫的方法，對數據庫進行操作

public String getName()

{

Cursor cursor = db.rawQuery("select name from logininf", null);

cursor.moveToFirst();

return cursor.getString(0);

}

public int changePWD(String oldP,String pwd)

{

ContentValues values = new ContentValues();

values.put("pwd", pwd);

return db.update("logininf", values,"pwd="+oldP, null);

}

}