一：创建数据库

package com.itcode.mysqlite;

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

/**
 * 继承SQLiteOpenHelper，创建数据库
 * @author Administrator
 *
 */
public class MySQLiteOpenHelper extends SQLiteOpenHelper{

	//一：声明构造函数
	/**
	 * @param context 当前应用的环境，用来确定数据库目录
	 * @param name  数据库文件的名字
	 * @param factory 游标工厂，用来创建结果集对象
	 * @param version 数据库版本 从1开始
	 */
	public MySQLiteOpenHelper(Context context) {
		super(context, "itcode.db", null, 1);
	}

	//二：重写onCreate方法 数据库被创建时调用 
	public void onCreate(SQLiteDatabase db) {
		System.out.println("MySQLiteOpenHelper-->onCreate 被调用！");
		//1.创建数据库
		db.execSQL("create table account(_id INTEGER PRIMARY KEY AUTOINCREMENT,name VARCHAR(20),balance INTEGER)");
//		db.execSQL("CREATE TABLE account(_id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR(20))");	// 执行一条SQL语句

	}
	//三：重写onUpgreade方法，数据库时调用
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
//		System.out.println("MySQLiteOpenHelper-->onUpgrade 被调用");
//		db.execSQL("alter table account ADD balance integer");
//		db.execSQL("ALTER TABLE account ADD balance INTEGER");

	}

}

二：对数据库进行CRUD操作

package com.itcode.mysqlite;


import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;

public class AccountDao {
	//一：创建AccountDao时依据当前context创建数据库
	private MySQLiteOpenHelper mySQLiteOpenHelper;
	public AccountDao(Context context){
		mySQLiteOpenHelper = new MySQLiteOpenHelper(context);
	}
	//二：增:传进来一个Account,将此对象加入数据库
	public int add(Account a){
		//1.获取相应的(可写的)数据库
		SQLiteDatabase writableDatabase = mySQLiteOpenHelper.getWritableDatabase();
		//2.执行语句
		writableDatabase.execSQL("insert into account(name,balance) values(?,?)", new Object[]{a.getName(),a.getBalance()});
		//3.获取插入的数据集：
		Cursor rawQuery = writableDatabase.rawQuery("select _id from account order by _id desc limit 1", null);
		rawQuery.moveToNext();
		int id = rawQuery.getInt(rawQuery.getColumnIndex("_id"));
		//4.关闭数据库
		return id;
	}
	//三：删：根据id删除数据库中相应的数据项
	public  void delete(int id){
		//1.获取相应的(可写的)数据库
		SQLiteDatabase writableDatabase = mySQLiteOpenHelper.getWritableDatabase();
		//2.执行删除语句
		writableDatabase.execSQL("Delete from account where _id = ?",new Object[]{id});
		//3.关闭数据库
		writableDatabase.close();
	}
	//四：改：传进来一个Account，根据Account的对象的id修改name 和balance
	public void update(Account a){
		//1.获取相应的（可写的）数据库
		SQLiteDatabase writableDatabase = mySQLiteOpenHelper.getWritableDatabase();
		//2.执行更新语句
		writableDatabase.execSQL("update account set name=?,balance = ? where _id = ?",new Object[]{a.getName(),a.getBalance(),a.getId()});
		//3.关闭数据库
		writableDatabase.close();
	}
	//五：查：根据id查询数据库
	public Account query(int id){
		//1.获取相应的（可读的）数据库
		SQLiteDatabase readableDatabase = mySQLiteOpenHelper.getReadableDatabase();
		//2.执行更新语句
		Cursor rawQuery = readableDatabase.rawQuery("select * from account where _id=?",  new String[]{String.valueOf(id)});
		//3.将查询到的数据赋值给Account对象
		Account a = null;
		while(rawQuery.moveToNext()){
			Integer balance = Integer.valueOf(rawQuery.getString(rawQuery.getColumnIndex("balance")));
			String name = rawQuery.getString(rawQuery.getColumnIndex("name"));
			a = new Account(id,name,balance);
		}
		//3.关闭结果集与数据库
		rawQuery.close();
		readableDatabase.close();
		return a;
	}
	//六：查询所有，将查询到的所有数据放在list集合中返回
	public List<Acco