How do I get the hash generated after updates?
thufir@dur:~$
thufir@dur:~$ mysql -u root -p
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mysql> use nntp;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show tables;
+---------------------+
| Tables_in_nntp |
+---------------------+
| articles |
| newsgroups |
| newsgroups_articles |
+---------------------+
3 rows in set (0.00 sec)
mysql> describe newsgroups;
+-----------+----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+----------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| newsgroup | longtext | NO | | NULL | |
| hash | char(32) | NO | | NULL | |
+-----------+----------+------+-----+---------+----------------+
3 rows in set (0.00 sec)
mysql> show triggers;
+-----------+--------+------------+-----------------------------------------------------+--------+---------+----------+----------------+----------------------+----------------------+--------------------+
| Trigger | Event | Table | Statement | Timing | Created | sql_mode | Definer | character_set_client | collation_connection | Database Collation |
+-----------+--------+------------+-----------------------------------------------------+--------+---------+----------+----------------+----------------------+----------------------+--------------------+
| make_hash | INSERT | newsgroups | BEGIN
set new.hash = md5(new.newsgroup);
END | BEFORE | NULL | | root@localhost | utf8 | utf8_general_ci | latin1_swedish_ci |
+-----------+--------+------------+-----------------------------------------------------+--------+---------+----------+----------------+----------------------+----------------------+--------------------+
1 row in set (0.00 sec)
mysql>
mysql>
mysql> DELIMITER $$
mysql>
mysql> USE `nntp`$$
Database changed
mysql> CREATE
-> TRIGGER `nntp`.`make_hash_update`
-> AFTER UPDATE ON `nntp`.`newsgroups`
-> FOR EACH ROW
-> BEGIN
-> set old.hash = md5(new.newsgroup);
-> END$$
ERROR 1362 (HY000): Updating of OLD row is not allowed in trigger
mysql>
mysql> quit;
-> exit
-> ^CCtrl-C -- exit!
Aborted
thufir@dur:~$
Also, from the workbench, I see the old trigger:
but don’t see how to add an additional trigger.
It’s not after update, it’s before update, and new. Don’t quite understand the syntax, but this at least doesn’t generate syntax errors. Would’ve like to have use the workbench: