SQLiteDataBase数据库的使用



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;  
        }  
    }