Bin-Blog » Database

Interactive SQL Tutorial

Binny V A — Tue, 10 Feb 2009 19:00:44 +0000

I have completed a tutorial that I have been working on for a long time. Its the Interactive SQL(Structured Query Language) Tutorial – it teaches you the basics of SQL. SQL, for those of you who are unaware of it, is the language used to access and manipulate data within a database. It is very simple and very powerful.

Interactive SQL Query Box

The cool thing about the tutorial is that it is interactive – each vistor can have a personal sandboxed database in which they can run any query they want. I call it the interactive query box. You can test almost all the SQL statements in this box without worrying about data loss – all the data is stored temporarily in this system. But you will have to install an extension called Google Gears in your browser.

Google Gears

Google Gears is an open source browser extension that lets developers create web applications that can run offline. You can install it in Firefox and Internet Explorer. If you want to try out SQL queries as it is presented in the tutorial, you need this extension.

You can view the tutorial without this extension, but you will be missing out the coolest feature of the tutorial.

Simple Tutorial

I have tried to make the tutorial as simple as possible. If you have learned about RDBMS, you know there are stuff like Normal Forms and Cardinality and other brain numbing definitions. I have removed all but the most essential definitions in my tutorial – it makes it easier to understand.

Even after removing the confusing definitions, I have apologized about the rest…

Sorry if you find the definitions here a bit too much. Trust me – you are much better off here than if you are learning SQL from a database book. They are going to lay definitions on you till your eyes bleed. I have seen brave men die from too much exposure to definitions.

Its Funny

I have learned a lot of languages and programming techniques by reading books and sites – and one thing I have noticed is that most of the material is unbelievably dry. Its extremely hard to keep your eyes open when you read them. That is why head first books are so popular – they made learning fun.

Its been a policy of mine to inject humor into such tutorials – if you have read any of my earlier tutorials, you would know that…

Also, I am a humor blogger – so this stuff comes easily to me.

What I am trying to say is that the new SQL tutorial follows the same pattern – there is a lot of humor in it. So people can read it easily – without resorting to caffeine shots.

I Want Your Help…

Now that the writing part is over, I am proof-reading it. I have corrected a fair amount of stupid mistakes so far – but I am sure that there are many still left. I was hoping that a few of you would head over to my SQL Tutorial and go through it. If you notice any mistakes, just put it in the comment field at the end of each page. Once I fix an error, I’ll remove the comment – that way, when I launch the tutorial, people will think that there were no errors in my tutorial. Devious, isn’t it?

Mastering phpMyAdmin: A Review

Binny V A — Wed, 26 Nov 2008 18:12:20 +0000

Some time ago, I was approached by the publisher of the book to write a review of their book ‘Mastering phpMyAdmin 2.11 for Effective MySQL Management by Marc Delisle[Affiliate link]‘. This got a bit delayed because of the plugin week. But I managed to finish the book today – so here is the review. Bottom line – most people are using phpMyAdmin for only the most basic operations(editing data, import, export, etc.). If you are one of them, you don’t need the book – you already know all you need to know about phpMyAdmin. But other(like me) use it for advanced purposes – to manage MySQL, create database/tables, run queries, etc. I would recommend you get this book. It covers everything from basic usage(which is a bit boring and should be skipped over) to advanced stuff(like designer view, configuration options, triggers, innoDB relation options etc.)

Its an interesting book – I found it easily readable if you skip over the basic stuff. If you think you already know what a section is talking about, skip over to the next section – that way, you will not be bored. Because it covers the basics in a fairly comprehensive way(think two screenshots per page(!), most of the things in the book you might already know. But there will be some interesting new tips as well. Some tips I found out by reading the book….

In the phpMyAdmin forms(like say, table creation form or row editing form), you can use the Ctrl+Arrow key combination to move the focus around.
If you create a Query bookmark with the same name as a table, that query will be used when you hit the ‘Browse’ tab.
If you are using a blob to store images within the database, there is a way to show the image(Browser Transformations, Chapter 16) in the browse view.
And more…

These are the chapters you should definitely read – some great tips can be found there…

Chapter 11: Relational System
Chapter 14: Bookmarks
Chapter 16: MIME-Based Transformations
Chapter 18: MySQL 5 Features

This should give you an idea of what to expect…

Preface
Chapter 1: Introducing phpMyAdmin
- PHP and MySQL: The Leading Open-Source Duo
- What is phpMyAdmin?
- History
- Awards
- phpMyAdmin Features Summary
- Summary
Chapter 2: Installing phpMyAdmin
- System Requirements
- Downloading the Files
- Installation
- First Connection Configuration
- Multi-Server Configuration
- Advanced Authentication
- Security
- Upgrading phpMyAdmin
- Summary
Chapter 3: Interface Overview
- Panels and Windows
- Language Selection
- Themes
- Left Panel
- Right Panel
- Query Window
- Site-Specific Header and Footer
- MySQL Documentation Links
- Summary
Chapter 4: First Steps
- Database Creation
- Creating Our First Table
- Manual Data Insertion
- Browse Mode
- Creating an Additional Table
- Summary
Chapter 5: Changing Data
- Edit Mode
- Multi-Row Editing
- Editing the Next Row
- Deleting Data
- Deleting Tables
- Deleting Databases
- Summary
Chapter 6: Changing Table Structures
- Adding a Field
- Editing Field Attributes
- TEXT
- BLOB (Binary Large Object) Fields
- ENUM and SET
- DATE, DATETIME, and TIMESTAMP
- Bit
- Index Management
- Summary
Chapter 7: Exporting Structure and Data
- Dumps, Backups, and Exports
- Database Exports
- Table Exports
- Selective Exports
- Multi-Database Exports
- Saving the Export File on the Server
- Memory Limits
- Summary
Chapter 8: Importing Structure and Data
- Limits for the Transfer
- Importing SQL Files
- Importing CSV Files
- Web Server Upload Directories
- Summary
Chapter 9: Searching Data
- Single-Table Searches
- Complete Database Search
- Summary
Chapter 10: Table and Database Operations
- Table Maintenance
- Changing Table Attributes
- Renaming, Moving, and Copying Tables
- Multi-Table Operations
- Database Operations
- Summary
Chapter 11: The Relational System
- Relational MySQL?
- Linked-Tables Infrastructure
- Defining Relations with the Relation View
- Defining Relations with the Designer
- Benefits of the Defined Relations
- Column-Commenting
- Summary
Chapter 12: Entering SQL Commands
- The SQL Query Box
- The Query Window
- Multi-Statement Queries
- Pretty Printing (Syntax-Highlighting)
- The SQL Validator
- Summary
Chapter 13: The Multi-Table Query Generator
- Choosing Tables
- Column Criteria
- Automatic Joins
- Executing the Query
- Summary
Chapter 14: Bookmarks
- Creating a Bookmark after a Successful Query
- Storing a Bookmark before Sending a Query
- Multi-Query Bookmarks
- Recalling from the Bookmarks List
- Public Bookmarks
- The Default Initial Query for a Table
- Bookmark Parameters
- Executing Bookmarks by Browsing the pma_bookmark Table
- Summary
Chapter 15: System Documentation
- The Database Print View
- The Selective Database Print View
- The Table Print View
- The Data Dictionary
- Relational Schema in PDF
- Summary
Chapter 16: MIME-Based Transformations
- The MIME Column’s Settings
- Requirements for Image Generation
- Examples of Transformations
- Summary
Chapter 17: Character Sets and Collations
- Language Files and UTF-8
- Versions of MySQL Prior to 4.1.x
- MySQL 4.1.x and Later
- Kanji Support
- Summary
Chapter 18: MySQL 5.0 Features
- Observations on the History of MySQL 5.
- Views
- Routines: Stored Procedures and Functions
- Triggers
- Information_schema
- Profiling
- Summary
Chapter 19: MySQL Server Administration
- Entering the Server View
- Database Information
- Server Operations
- Summary
Chapter 20: Troubleshooting and Support
- System Requirements
- Base Configuration
- Solving Common Errors
- Seeking Support
- Contributing to the Project
- Future phpMyAdmin Versions
- Summary
- Index
A final advice before leaving – buy the dead tree edition if possible. The ebook(PDF) has DRM which makes it very hard to read. You have to enter the password every single time you open the file. Its really annoying after a while.

My Other phpMyAdmin Posts
- Installing phpMyAdmin 2.8
- phpMyAdmin Tips and Tricks – Database Backup and Restore
- Installing and Configuring phpMyAdmin
- Managing Databases with MySQL Clients – phpMyAdmin
Related Links
- Sample Chapter: Table and Database Operations
- Mastering phpMyAdmin Book Details
- review: Mastering phpMyAdmin 2.11 for Effective MySQL Management
- Book review: “Mastering phpMyAdmin 2.11 for Effective MySQL Management” by Marc Delisle

Remote Database Backup WordPress Plugin

Binny V A — Mon, 13 Oct 2008 16:43:10 +0000

I have released my second WordPress Plugin – Remote Database Backup. Its is based on the WordPress Database Backup plugin. If you are a regular wordpress user, you might be better off using WordPress Database Backup plugin instead of my version. But if you, like me, have a local server on your system and has a copy of your site on the local server as well as the online server, you will find great use for my plugin.

My plugin is designed to make it possible to remotely create and download wordpress database backup in form of SQL dumps. You can then use these dumps to sync the local version of your site with the online version.

Backuping your WordPress Database

Install Remote Database Backup Plugin in WordPress
Login to WordPress site
Go to the Backup Page(Manage > DB Backup)
Create a backup
Download the backup file to your system

Sync With Local Server

And if you have a local version of your site, you can sync it with the online site using the backup file. Just follow these steps…

Extract the backup file(its in the tar.gz format)
Import it into your mysql database.
Make some changes to the database(like set the home url) so that wordpress works locally

Automation Script

You can do all these steps manually – or you can use the automation script I have cooked up. You need PHP installed in your system for this to work(I assume you already have PHP if you have a local version of wordpress).

To use the script, first install the plugin. Then download the script and rename it to ‘backup.php’(the extension must be ‘php’ instead of ‘txt’. Now open it in your favorite editor and change the variables to match your site. You can run it by opening a terminal/command prompt and navigating to that folder and executing the command ‘php backup.php’. This will automatically make a backup and sync it with your local database.

Need Feedback

Let me know how it works for you if you are installing the plugin – its the first release – so I need some feedback.

Installing LAMP(Apache Web Server/PHP/MySQL) in Debian/Ubuntu

Binny V A — Mon, 15 Sep 2008 19:10:07 +0000

Installing the LAMP environment on a Linux system is easy if you are comfortable with using the native package management software. If you on a Red Hat/Fedora/CentOS system, that will be yum – and for Debian/Ubuntu systems, that will be apt. This tutorial shows you how to install Apache 2, PHP 5 and MySQL 5 in Debian using apt.

Before installation, a few points to remember. These instruction are not for a production environment – this is for a development environment. To install the software, you need root access. You can get that using this command…

su -
[Enter root password]

Installing Apache 2

Use this command to install Apache 2.

apt-get install apache2

Make sure you specify ‘apache2′ – or else, apache 1.3 will be installed.

Install PHP 5

Now, install the PHP 5 packages…

apt-get install libapache2-mod-php5 php5-cli php5-common php5-cgi

No go to the folder /etc/apache2/sites-enabled/ and edit the file in that directory(usually 000-default). Find the line that says
RedirectMatch ^/$ /apache2-default/
and remove it.

Now your document root is /var/www/ – place all your HTML documents and scripts in this folder. If you want to make some other configuration changes, edit the configuration files at /etc/apache2/apache2.conf

I also had to make the following changes…

Changed the owner of /var/log/apache2 to www-data – I used the command chown www-data:www-data apache2
Created an empty file at /etc/apache2/httpd.conf

This was to fix a few errors I saw on my system – you may not have to do it.

Install MySQL

This is the command to install MySQL server, its client and PHP’s MySQL libraries…

apt-get install mysql-client mysql-common mysql-server php5-mysql

Finally, Install the other packages you need as well

apt-get install php5-sqlite php5-gd ...

Testing the System

Go to your document root(/var/www) and create a php files called ‘info.php’ and put this code inside that…

info();

Start the Servers

First, turn on the MySQL database server…

/etc/init.d/mysql start

Then, start the Apache Web Server…

/etc/init.d/apache2 start

Now fire up a browser and go to localhost – you should see a file listing page with a ‘info.php’ in the list. Click on that link – if you see a PHP information page, your web server is setup correctly.

To make sure MySQL-PHP connection is working, install phpMyAdmin – or write a database connection script – whatever is easier for you.

Document Formats

Binny V A — Thu, 03 Apr 2008 18:20:39 +0000

In FLOSS circles, March 26 is celebrated as the Document Freedom Day.

Document Freedom Day (DFD) is a global day for document liberation. It will be a day of grassroots effort to educate the public about the importance of Free Document Formats and Open Standards in general.

This is when I realized that people actually use the office packages daily. I almost never use it. According to me there are three options to store text data.

Plain Text
HTML
Database

Plain Text

The simplest format there is. If there is something I should remember, I just put it in a text file and save it to the desktop. I used to use it a lot earlier – but I don’t use it much nowadays due to searchability issues. There are quite a few advantages in using the text format

HTML

If I need any formatting in the text, I create the document in HTML. It is easier for me to create the formatting using HTML code that using WYSIWYG Word Processors(like MS Word). I write all my blog posts in HTML – perhaps the only occasion where I need formatting.

Database

My favorite method to store text data is in a database. I am a web developer – so I always have a Web Server and Database server running on my system – so this system is perfect for me.

Interface

Remove that scared look on your face – I don’t use phpMyAdmin or any Database Administration tools as the interface to save/view the data. I use my own custom scripts or WordPress.

The best example of this is txt. Txt is my code snippets/commands repository. You can view the full story in the Saving Code Snippets post.

That’s an online example – I also have a personal wordpress blog running in my local server. I use it to record events, purchases, store receipts etc.

Advantages

Tagging: Tagging is heaven-sent to make information more findable – any del.icio.us user should know that. I used to install Ultimate Tag Warrior to get this feature – but WordPress now supports tags natively.
Searching: Searching for data within a database is much more easier, faster and provides more relevent results than searching for the data in a collection of file. Even if you are using a file indexing software like Google Desktop Search or Beagle/Recoll(for linux users), I find database searching more easier. Another advantage of using database to search is that you can create complex queries if you know SQL.

Disadvantages

Not for everyone: Let’s face it – installing and maintaining a web/database server is a tad in the geek zone. An average Joe will find it just a little bit out of their league.
Overhead: Running a web server and a database server is a bit demanding on the RAM.
Backing up a little more complicated – but easier: Backing up the data in a Database is not as straight forward as backing up files – but its actually easier if you know how.

Online

One extra method to store the data – online. This data is stored in a database – but you don’t have the disadvantages associated with using a database. More and more people are turning to this method now. I did not include it in the initial list because its not a data format – its more of a data storing method.

3 Simple Steps to create a Web Installer

Binny V A — Fri, 06 Jul 2007 16:00:48 +0000

Creating a web installer is not hard – as a matter of fact – it is downright easy. You just have to know a few things. Get the database details, create the database, save the details. That’s it!

Getting Database Details

A simple four field form will suffice. The important thing to remember is that the data must be saved as session variables – as we are using a multi-page form.

As soon as you get the DB details, try to connect to the database and confirm that the DB details is correct. If the connection attempt fails, take the user back to the DB details form. Else go to step two.

Insert Initial Data

This part is easy – just run a bunch of SQL statements to create the necessary table structure and insert the initial data.

Save the Details

This should be the last step of the installation. Just take all the data from the session variables and write it to a file, say ‘configuration.php’. Write the data as PHP code – so all you have to do to retrieve the data is include the file.

The code for the installer in the next post.