mysql - select + 函数操作

查询端口号：

mysql> select @@port;
+--------+
| @@port |
+--------+
|   3318 |
+--------+
1 row in set (0.00 sec)

查询数据保存路径：

mysql> select @@datadir;
+-----------------------------+
| @@datadir                   |
+-----------------------------+
| /root/mysql/data/3318/data/ |
+-----------------------------+
1 row in set (0.00 sec)

查询socket路径：

mysql> select @@socket;
+---------------------+
| @@socket            |
+---------------------+
| /tmp/mysql3318.sock |
+---------------------+
1 row in set (0.00 sec)