随手记（二）

MySQLiteHelper.java
public class MySQLiteHelper extends SQLiteOpenHelper {

    //抽象类必须调用父类方法
    public MySQLiteHelper(Context context, String name, CursorFactory factory, int version) {
            //调用父类构造函数
            super(context, getMyDatabaseName(name), factory, version);
    }

    private static String getMyDatabaseName(String name){
            String databasename = name;
            boolean isSdcardEnable = false;
            String state = Environment.getExternalStorageState();
            if(Environment.MEDIA_MOUNTED.equals(state)){//SDCard是否插入
                    isSdcardEnable = true;
            }
            String dbPath = null;
            if(isSdcardEnable){
                    dbPath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Finance/database/";
            }else{//未插入SDCard，建在内存中

            }
            File dbp = new File(dbPath);
            if(!dbp.exists()){
                    dbp.mkdirs();
            }
            databasename = dbPath + databasename;
            return databasename;
    }
    /**
     * 当数据库首次创建时执行该方法，一般将创建表等初始化操作放在该方法中执行.
     * 重写onCreate方法，调用execSQL方法创建表
     */
    @Override
    public void onCreate(SQLiteDatabase db) {
            Log.i("SWORD", "create a Database");
            //创建数据库sql语句
            String sql = "create table finance(ID integer PRIMARY KEY AUTOINCREMENT,Type varchar(10),Time varchar(20),Fee double,Remarks varchar(20),Budget varchar(10))";
            //执行创建数据库操作
            db.execSQL(sql);

            //创建表
             sql = "create table plan(ID integer PRIMARY KEY AUTOINCREMENT,Morningplan varchar(100),Afternoonplan varchar(100),Nightplan varchar(100),Rank varchar(5), Conclusion varchar(100))";
            //执行创建数据库操作
            db.execSQL(sql);
    }

    @Override
    //当打开数据库时传入的版本号与当前的版本号不同时会调用该方法
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

    }

}