mysql> select @host:=host from mysql.user where host!='localhost';
+----------------+
| @host:=host   |
+----------------+
| 127.0.0.1    |      --> set @host:='127.0.0.1';
| ::1        |      --> set @host:='::1'; | wonhigh-test16 |      --> set @host:='wonhigh-test16'; +----------------+
mysql> select @host;     ---查询时只会取最后一行....不会是自己想的3行都显示；
+---------------+
| @host       |
+----------------+
| wonhigh-test16 |
+----------------+
mysql> mysql> select host,@rownum:=@rownum+1 AS rownum  from mysql.user,(SELECT @rownum:=0) r where host!='localhost';
+-----------------+--------------+
| host        | rownum     |
+-----------------+--------------+
| 127.0.0.1     |    1    | | ::1         |    2    | | wonhigh-test16  |    3    | +------------------+--------- - --+ mysql> set @rownum:=0;
select host,@rownum:=@rownum+1 AS rownum  from mysql.user where host!='localhost'; mysql>select @host:= GROUP_CONCAT (host) host1 from mysql.user where host!='localhost';
+---------------------------------+
| host1                 |
+--------------------------------+
| 127.0.0.1,::1,wonhigh-test16  |
+---------------------------------+
mysql> mysql> SELECT  substring_index(substring_index(a.host1, ',', b.id),',' ,-1 ) as host1_ ,b.id
FROM (select @host:=GROUP_CONCAT(host) host1 from mysql.user where host!='localhost') a
JOIN  (select 1 id union all select 2 union all select 3)  b ON b.id<= (length(a.host1) - length(REPLACE(a.host1, ',', '')) + 1) order by b.id; +-------------------+---------------+ | host1_       |     id    | +------------------+-----------------+ | 127.0.0.1     |    1     | | ::1         |    2     | | wonhigh-test16 |     3     | +-----------------+----------------+ mysql>

广播电视节目制作经营许可证(京) 字第1234号 中国互联网协会会员