Hafidz Zulkifli

Several useful commands. Basic Retrieval from single table SELECT [DISTINCT] display_fields FROM tables WHERE field_conditions ORDER BY field_name [ASC | DESC]; e.g: select * from MethodParameter; e.g: select * from MethodParameter where NAME=DUNHAM; Delete the whole content of table DROP TABLE tablename ; e.g: drop table MethodParameter; Delete one or more records from a table DELETE FROM table_name WHERE record_retrieval_conditions ; e.g: delete from MethodParameter where NAME='DUNHAM BUSH';

Should you ever see these types of message, there are several 'must-know' unix commands that can be used in order to start investigating. 1. du | sort -n : lists all file usage from smallest to largest. 2. df -k -b : see how much allocation is used in the directory. For more help, go to links below:- 1. An IT-admin guide to clearing up disk space 2. df unix command definitions and usage 3. du unix command definitions and usage

From http://www.ncl.ac.uk/iss/unix/unixhelp/kill.html and http://www.decf.berkeley.edu/help/unix/kill.html If you are logged in to a Unix system and your session "hangs" or "freezes" (i.e. nothing happens for a long time and it does not respond to Ctrl/Q Ctrl/C or Ctrl/D), you can attempt to unfreeze it yourself by "killing" the process which has stopped your session. You can also use Ctrl/Z to get out of a process in UNIX. Login to the system where your session is frozen Type the command: w usid where usid is your own username. This will produce a line of output for each login something like this: 9:53am up 82 day(s), 15:58, 132 users, load average: 6.50, 6.25, 5.70 User tty login@ idle JCPU PCPU what nabc pts/160 9:12am -csh nabc pts/166 9:53am w nabc Note the contents of the tty column for the frozen login -- in this example attached to pts/...