Android SQLiteDatabase的使用

package com.shawn.test;

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

public class DatabaseAdapter{

    private static final String DB_NAME = "Test.db";    //数据库名
    private static final int    DB_VERSION = 1;         //数据库版本

    private static final String DB_TABLE = "my_order";  //表名
    private static final String KEY_ID = "_id";         //id
    private static final String KEY_ORDER_ID = "order_id";  //订单号
    private static final String KEY_TYPE = "_type";         //订单类型
    private static final String KEY_STATE = "_state";       //订单状态

    private Context context;
    private DatabaseHelper mDatabaseHelper;
    private SQLiteDatabase mSQLiteDatabase;

    private static class DatabaseHelper extends SQLiteOpenHelper{
        //创建数据库语句
        private static final String DB_CREAT = "CREATE TABLE "
                + DB_TABLE
                + " (" + KEY_ID + " INTEGER PRIMARY KEY,"
                + KEY_ORDER_ID + " TEXT,"
                + KEY_TYPE + " INTEGER,"
                + KEY_STATE + " INTEGER)";

        public DatabaseHelper(Context context) {
            super(context, DB_NAME,  null , DB_VERSION);
        }
        @Override
        public void onCreate(SQLiteDatabase db) {
            // TODO Auto-generated method stub
            db.execSQL(DB_CREAT);
        }
        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            // TODO Auto-generated method stub
            db.execSQL("DROP TABLE IF EXISTS "+DB_TABLE);
            onCreate(db);
        }
    }

    public DatabaseAdapter(Context context) {
        this.context = context;
    }
    //开启
    public void open() {
        mDatabaseHelper = new DatabaseHelper(context);
        mSQLiteDatabase = mDatabaseHelper.getWritableDatabase();
    }
    //关闭
    public void close() {
        mSQLiteDatabase.close();
        mDatabaseHelper.close();
    }

    //增
    public long insertData(String orderId, int type) {
        ContentValues values = new  ContentValues();
        values.put(KEY_ORDER_ID, orderId);
        values.put(KEY_TYPE, type);
        values.put(KEY_STATE, Config.STATE_APPLY);
        long id = mSQLiteDatabase.insert(DB_TABLE, KEY_ID, values);
        return id;
    }
    //删
    public boolean deleteData(Context context, long id) {
        boolean delete = mSQLiteDatabase.delete(DB_TABLE, KEY_ID + "=" +id, null)>0;
        return delete;
    }
    //改
    public boolean updateData(long id, int state) {
        ContentValues values = new  ContentValues();
        values.put(KEY_STATE, ""+state);
        boolean update = mSQLiteDatabase.update(DB_TABLE, values, KEY_ID + "=" +id, null)>0;
        return update;
    }
    //查
    public Cursor fetchData(String selection) {
        Cursor mCursor = mSQLiteDatabase.query(DB_TABLE, new String[]{KEY_ID, KEY_ORDER_ID, KEY_TYPE, KEY_STATE}, selection, null, null, null, null);
        if(mCursor != null)
            mCursor.moveToFirst();
        return mCursor;
    }
}