http://dev.mysql.com/doc/refman/5.1/ja/group-by-functions.html GROUP_CONCAT(expr) ãã®é¢æ°ã¯ãã°ã«ã¼ãããã®é£çµãããé NULL å¤ãä¼´ãã¹ããªã³ã°çµæãæ»ãã¾ããéNULL å¤ããªãå ´å㯠NULL ãæ»ãã¾ããMySQL ã§ã¯ãå¼ã®ã³ã³ããã¼ã·ã§ã³ã®é£çµãããå¤ãå¾ããã¨ãã§ãã¾ããDISTINCT ã使ç¨ãããã¨ã§ãéè¤ããå¤ãé¤ããã¨ãå¯è½ã§ããçµæã®å¤ãã½ã¼ããããå ´åã¯ãORDER BY å¥ã使ç¨ãã¦ãã ãããéé ã§ã½ã¼ãããã«ã¯ãDESC ( éé ) ãã¼ã¯ã¼ãããORDER BY å¥ã®ã½ã¼ãããã«ã©ã ã®ååã«å ãã¦ãã ãããããã©ã«ãã§ã¯æé ã«ãªã£ã¦ãã¾ããããã¯ãASC ã使ããã¨ã§æ示çã«æå®ãããã¨ãã§ãã¾ããSEPARATOR ã®å¾ã«ã¯ãçµæã®å¤ã®éã«æ¿å ¥ãããã¹ãã¹ããªã³ã°å¤ãç¶
{{#tags}}- {{label}}
{{/tags}}