ContentProvider-SQLiteOpenHelper简化数据库/表 创建更新(2)

修改上篇文章的例子:

1.建立常数类

/** * @author Lean */public class DBConstant {public static final String DB_NAME="MyFirstDbStorage";public static final int DB_VERSION=1;public static final String TABLE_NAME = "'user_info_tab'";}

/** * @author Lean */public class TableConstant {public static final String COLUMN_USERNAME="userName";public static final String COLUMN_USERADDRESS = "userAddress";}

 2.简化数据库创建,更新

/** * @author Lean */public class DbHelper extends SQLiteOpenHelper {public DbHelper(Context context) {super(context, DBConstant.DB_NAME, null, DBConstant.DB_VERSION);}@Overridepublic void onCreate(SQLiteDatabase sqliteDb) {String sql="create table if not exists "+DBConstant.TABLE_NAME+" ("+TableConstant.COLUMN_USERNAME+" vachar(50),"+TableConstant.COLUMN_USERADDRESS+" vachar(50));";sqliteDb.execSQL(sql);}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {}}

3.修改之前调用源码

/** * @author Lean */public class FirstDbOperation {private Context mContext;public FirstDbOperation(Context context){this.mContext=context;}public SQLiteDatabase OpenOrCreateDBStorage(){return new DbHelper(mContext).getWritableDatabase();}}