Study and You Shall Learn

Originally this blog started as a reference for people moving from Oracle to MySQL, over the course of the 5 or so months it's been going I have at times moved away from that and on to other topics. I have tended however to keep it technical and avoided commenting on anything related to the business side of MySQL. Since Christmas my MySQL activities have decreased somewhat but over the last few weeks I've been doing more and more, be that attempting to update this blog or work on new content on www.mysqldevelopment.com. One of the things I have decided to do is take the MySQL certification exams, this isn't some great announcement and I'm a little wary of doing so publicly because I don't want to set a time limit on doing so.

Anyway on to the point, I have been developing with databases from the very first day of my IT career, mostly this has been with Oracle but also with Microsoft SQL Server, FoxPro, DB2 and Ingress. This has meant that I have picked up a lot of knowledge about databases and also SQL. On the whole this has meant that moving to MySQL has been painless, the few things that I needed to know specifically for MySQL have been easy to pick up. But having started to read the certification study guide I can see that there are gaps in my knowledge. Most of these are just small things that while are good to know are not a problem in the day to day operation of MySQL. However there are some really useful things that I have picked up, things which I just wouldn't have known or thought about had I not read the guide or been told by somebody in the know. I'm sure I'll be posting about more this in the future but here is a small tip I picked up.

Firstly it's \c, that may be something you use all the time but having worked with Oracle for so long I just got used to entering some rubbish to make the client give me a fresh line. If you like me are unfamiliar with \c then all it does is cancel and clear the command line if you make a mistake while entering a statement. In the old days I would have done something like this....

mysql> selec t * from emps
    -> where ;
ERROR 1064 (42000): You have an error in your SQL 
syntax; check the manual that corresponds to 
your MySQL server version for the right syntax to 
use near 'selec t * from emps where' at line 1
mysql>

While I was on the second line I noticed that I had incorrectly typed the SELECT keyword so I terminated the statement by simply entering the ; delimiter. While this doesn't do any harm it does produce an error. Using \c we can do this gracefully like so.

mysql> selec t * from emps
    -> where \c
mysql>