MySQL Archives - A.R. ZERINA.R. ZERIN

MySQL

July 9, 2025

Getting MySQL Database Storage Sizes If you’re managing a MySQL database, it’s essential to monitor how much disk space your tables and databases are consuming. Whether you’re troubleshooting performance issues or planning storage upgrades, knowing the exact size of your tables can be incredibly helpful. 📊 View Table Sizes in MySQL To get the size […]

Commands MySQL

Upgrading MySQL 5.6 to 5.7 – Group By Does not work anymore

ZERIN

September 17, 2019

Recently I have updated one of my server MySQL, then I have found that old MySQL Group By Query is not running anymore. It happens because of notorious nonstandard MySQL extension to GROUP BY Go To Mysql console: Type the below command & see what are current SQL mode: SELECT @@GLOBAL.sql_mode; Type the below command to […]

MySQL

MySQL how To – show open database connections

ZERIN

May 15, 2016

MySQL how To – show open database connections

MySQL Current Connection Query Information You can show MySQL open database connections (and other MySQL database parameters) using the MySQL show status command, like this: mysql> show status like 'Conn%'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Connections | 8 | +---------------+-------+ 1 row in set (0.00 sec) mysql> show status like '%onn%'; +--------------------------+-------+ […]

Commands Linux CentOS MySQL

Linux How to Find Files based on the File Size

ZERIN

May 13, 2016

If you want to search all the files that are more than 100MB in your linux server /var folder, type thee below command: # find /var -type f -size +100M To Know which directories are taking most spaces of the hard disk, type the below command in your Linux Console: # du -a /var | […]

Linux CentOS MySQL

MySQL: ERROR 1129 (HY000) Host 'Crowder' is blocked because of many connection errors

ZERIN

May 13, 2016

Type the below command in Linux Console Mode: # mysqladmin flush-hosts

MySQL

MySQL Command — Replace, Append command

ZERIN

February 5, 2016

To append a text after the content for a column: UPDATE `articles` SET introtext= concat(introtext, ‘</div>’); To add a text before the content for a column: UPDATE `articles` SET introtext= concat(‘<hr class=”system-pagebreak” /><div style=”display:none;”>’,introtext); To replace text in the content for a column: UPDATE `articles` SET introtext = REPLACE(introtext, ‘<hr class=”system-pagebreak” />’, ‘</div><hr […]