public int update(Person person) {
     Log.e("SQLite", "----update----");
     ContentValues values = new ContentValues();
     values.put("formcode", person.formCode);
     values.put("summary", person.summary);
     values.put("context", person.context);
     values.put("imagefolder", person.folder);
     SQLiteDatabase db = dbHelper.getWritableDatabase();
     db.beginTransaction();
     try {
         db.update(Person.TABLENAME, values , "id" + "=?",new String[] {person.id});
         db.setTransactionSuccessful();
     } catch (Exception e) {
         return 0;
     } finally {
         db.endTransaction();
     }
     db.close();
     return 1;
} 

/**
*
* @param table 表名
* @param columns 列名字符串数组
* @param selection 筛选条件
* @param selectionArgs 筛选条件参数数组
* @param groupBy 分组字段
* @param having
* @param orderBy 排序字段
* @return Cursor对象
*/

public Cursor query(String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy); Cursor c=db.query("draftbox" , columns, selection, selectionArgs,groupBy, having, orderBy);