mysql> create table A(a int);
Query OK, 0 rows affected (0.01 sec)

mysql> create table trace(tbname varchar(30),DML_type varchar(10),DML_time datetime,DML_user varchar(30),DML_IP varchar(30));
Query OK, 0 rows affected (0.01 sec)

create trigger insert_a after insert on  A1
for each row
insert into trace values (‘A1‘,‘INSERT‘,NOW(),substring_index(current_User(),‘@‘,1),substring_index(current_User(),‘@‘,-1));

mysql> insert into A values(1);
Query OK, 1 row affected (0.00 sec)

mysql> select * from trace;
+--------+----------+---------------------+----------+-----------+
| tbname | DML_type | DML_time | DML_user | DML_IP |
+--------+----------+---------------------+----------+-----------+
| A | INSERT | 2010-11-29 17:58:12 | root | localhost |
+--------+----------+---------------------+----------+-----------+
1 row in set (0.00 sec)

mysql> select * from trace;
+--------+----------+---------------------+----------+--------------+
| tbname | DML_type | DML_time | DML_user | DML_IP |
+--------+----------+---------------------+----------+--------------+
| A | INSERT | 2010-11-29 17:58:12 | root | localhost |
| A | INSERT | 2010-11-29 17:58:38 | cpc | 192.168.0.30 |
+--------+----------+---------------------+----------+--------------+
2 rows in set (0.00 sec)

mysql>