Holdorf.dk/Software

Software Development Blog

phpMyDumper released

After one week of coding I am ready to release my newest software project: phpMyDumper.

I wanted to do automatic backup of my website databases and normally you would do this using mysqldump and a cronjob. At the moment I am hosting my websites on my own server, but I plan to move the websites to an external webhost. However since I have no way to make sure that I have access to mysqldump on my future webhost especially if cost should be as low as possiible, I decided to write a php tool myself to do the job.

I googled for php scripts but many of them were based on using a webbrowser or the dump file format was not acceptable. I wanted the script to dump a file formatted just like phpMyAdmin.

At last I found MySQLDump 2.0 by Daniele ViganĂ², creativefactory.it. His php class was posted at coders4fun.com blog and after reading through the blog post, testing it on my databases and looking at the source code I decided to use his php class and improve it.

First it had a bug when importing its table structures of Joomla databases into MySQL using eg. phpMyAdmin. This was fixed when I rewrote it to use SHOW CREATE TABLE to construct database table structures. Also this simplified the code a lot! :) Furthermore, I added the AUTOINCREMENT statement to the table structures. This was important to me because I am developer of a webgame, that uses autoincrement as post ids in forums, messages ids and account ids etc…

Then I went on and added an option to make it format the dump file like phpMyAdmin. Originally the php class dumped all structures first and then all the data. But I wanted it to format the dump like phpMyAdmin dumping data right after the each table structure.

Also, the php class dumped expanded INSERT statements but I changed it to dump INSERT statements without field names and I made it optional to let the php class dump DROP TABLE and CREATE TABLE statements as well as the INSERT statements.

I used Thors code changes in his MySQLDump 2.01 version from the coders4fun.com blog. That includes the dash-bug and null not save bugfixes suggested by Petr ‘PePa’ Pavel and that the php class returns a stream, if no filename is provided. However, I forgot to document how to use the stream feature in the release example, but I will show that in a future post.

At last I optimized the code for dumping INSERT statements. The original code saved data to file when data reached 1MB. Checking the string with strlen() every cycle, however, that method used a lot of cpu power, so I changed it to save to file for each INSERT statement. This reduced the dumping time and cpu usage a lot, especially for large databases.

This example shows how to use phpMyDumper. Have fun with the php class! :D
[file path=”phpmydumper-1.00-example.php” tpl=”code”/]

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