I noticed fact recently that MySQL Table autoincrement Id value resets to zero, if table is empty.
solution to this is, you can reset the counter to
mysql> ALTER TABLE tbl AUTO_INCREMENT = 1000;
Tuesday, January 25, 2011
Wednesday, January 19, 2011
Crontab/Cron analyzed - not working issues
It has now become routine job to write shell scripts to schedule jobs on server. (Ubuntu)
Although its routine, still sometime we got stuck with same issues. so I thought lets write a small article
to type out common errors I made.
1) Path -
By default, in cron environment, no Path is defined, so you can not even run simplest of shell file with simple
command like 'date'
you need to define
PATH=/home/sandip/bin:/bin:/sbin:/usr/bin:/usr/sbin/$PATH
your script testCronFile.sh can reside in /home/user/bin. it should have 755 perms.
chmod 755 testCronFile.sh
additionally to make sure that Script is executing.
you can do it using following 2 ways..
1) sudo tail -f /var/log/syslog
You would see something like following..
Jan 19 10:08:01 localhost CRON[11593]: (root) CMD (testCronFile.sh)
2) In testCronFile.sh, You can include line like
echo "Testing Shell file" >> /home/sandip/cron.log
so after execution of script, cron.log file would get created with "Testing Shell file" written in it.
for accessing files under root permission from cron, use sudo
$ sudo crontab -e
You can add comments, if you have something else regarding cron files.
Although its routine, still sometime we got stuck with same issues. so I thought lets write a small article
to type out common errors I made.
1) Path -
By default, in cron environment, no Path is defined, so you can not even run simplest of shell file with simple
command like 'date'
you need to define
PATH=/home/sandip/bin:/bin:/sbin:/usr/bin:/usr/sbin/$PATH
your script testCronFile.sh can reside in /home/user/bin. it should have 755 perms.
chmod 755 testCronFile.sh
additionally to make sure that Script is executing.
you can do it using following 2 ways..
1) sudo tail -f /var/log/syslog
You would see something like following..
Jan 19 10:08:01 localhost CRON[11593]: (root) CMD (testCronFile.sh)
2) In testCronFile.sh, You can include line like
echo "Testing Shell file" >> /home/sandip/cron.log
so after execution of script, cron.log file would get created with "Testing Shell file" written in it.
for accessing files under root permission from cron, use sudo
$ sudo crontab -e
You can add comments, if you have something else regarding cron files.
Tuesday, January 04, 2011
MySQL export large data from command promt to CSV file
If you can cope with table-at-a-time, and your data is not binary, use the -B option to the mysql command. With this option it'll generate TSV (tab separated) files which can import into Excel, etc, quite easily:
% echo 'SELECT * FROM table' | mysql -B -uxxx -pyyy database
Alternatively, if you've got direct access to the server's file system, use SELECT INTO OUTFILE which can generate real CSV files:
SELECT * INTO OUTFILE 'table.csv'
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
LINES TERMINATED BY '\n'
FROM table
Courtesy:
Stack Overflow
http://stackoverflow.com/questions/467452/dump-a-mysql-database-to-a-plaintext-csv-backup-from-the-command-line
% echo 'SELECT * FROM table' | mysql -B -uxxx -pyyy database
Alternatively, if you've got direct access to the server's file system, use SELECT INTO OUTFILE which can generate real CSV files:
SELECT * INTO OUTFILE 'table.csv'
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
LINES TERMINATED BY '\n'
FROM table
Courtesy:
Stack Overflow
http://stackoverflow.com/questions/467452/dump-a-mysql-database-to-a-plaintext-csv-backup-from-the-command-line
Subscribe to:
Posts (Atom)
