Posts

Group by Date when Stored in Mysql DataBase as Date Time

I have a table called date_count with 2 columns one is a value and another is a date time, say called date_time in mysql. Date Time in mysql is stored as dd-mm-yy hh:mm:ss. The issue comes when I need to get the number of rows per day. As its stored as dat …

Generate Date from a range in Mysql and pad the results where no date is present

If you want to generate dates, MYSQL doesn’t have a range function, so I wrote a work around for the same. So how  it works is I have reused a code to generate numbers from my previous post. So I added date function to that query and reduce the generated  …

Generate 1 to 1000 in mysql

Sometimes its necessary to have thousand rows to join or generate new values, we need to get the thousand rows first. For this I used union of numbers 0-9.  I have joined four of these to get to four digit values. So here is the code:



SELECT @row := …

BSNL Dataone Auto Downloader

Bsnl(India) provides an account that has 2am to 8am unlimited download. It was not easy to wake up at 2am and switch on the computer and sleep again. So I tried to find a method to switch on the computer automatically at 2am and download and shutdown at 8a …

Customizing Mysql Prompt For multiple Servers

If you are using mysql regularly on multiple servers its really useful to have the promt in mysql to show something more than mysql>. It would be useful if it showed the username,hostname, current database and things like that. So how to do this. One m …

Check the port in which the Mysql is running on

Mysql can be configured to run other ports other than the default port (of 3306). So what will you do when you need to find the port on which a mysql server runs on. If you don’t have access to the server files and can access the server only using the mysq …

Check if a table exists in MySQL from PHP

Sometimes its necessary to execute a query or execute some code if a table exists or not. So a bit of searching got me to the conclusion that mysql doesn’t have a direct query or method for it from php. So there are two methods to do it. Use the mysql c …

Important MySQL DBA Interview Questions

Here are a few sets of interview questions expected for MySQL DBA position.These are compilation of the usual questions from various DBA texts: What is Log Switch? – The point at which ORACLE ends writing to one online redo log file and begins writing to …

Birthday Reminder For Gnome Panel

This program checks the file /home/rsrijith/shell/birthday_reminder.txt to find the upcoming birthdays in 20 days and writes into the file /home/rsrijith/shell/birthdays. There is a file called /home/rsrijith/shell/birthdays1, the difference between it and …

Batch Insert/Update for Mysql in Java

Large inserts/Updates are a costly operation. One foolish way that I used to do is to run each update or insert query one at a time. Its incredibly slow. With most of the systems currently the latency is what is killing the performance not the CPU. Hence l …