使用到mysql的一个函数group_concat
eg: SELECT group_concat(id,‘,‘) FROM bs_ticket where id < 700
result：
‘673,,674,,675,,676,,677,,678,,679,,680,,681,,682,,683,,684,,685,,686,,687,,688,,689,,690,,691,,692,,693,,694,,695,,696,,697,,698,,699,‘
原文：http://my.oschina.net/wanily/blog/353810