SQL Select Tutorials

As an author who also happens to have a technological background, writing this series of articles was an enjoyable experience. My intention while writing these articles was simple: to make an absolute beginner - enjoy the power and simplicity of the SQL language fully without overburdening the reader with other things.

The answer to “How far have I succeeded in my objective?” is best left to the readers of the articles. Unlike many other programming languages, I believe basic SQL can be most easily learnt. The SELECT clause is the only command you need to know the extract and format data from just about any supported database.

This series is divided into the following articles:

1)      Introduction to Relational Databases: Provides a contextual overview of the technical terms in database jargon.

2)      Introduction to the Select Clause: The SELECT clause in SQL is officially introduced. Its syntax and other little details are shown as well. The ORDER BY clause is iontroduced as well.

3)      SELECTING CONDITIONALLY: The WHERE clause and the logical and mathematical operators are introduced.

4)      SELECTING CONDITIONALLY PART – 2: The BETWEEN and IN operators are introduced.

5)      SELECTING CONDITIONALLY PART – 3 - text columns: Here is where textual comparison in SQL is delved into in detail.  The LIKE clause and computed columns are introduced as well.

6)      SELECTING CONDITIONALLY PART – 4 - functions: A brief look at some of the statistical functions in SQL namely MAX, MIN, AVG, SUM, COUNT etc. The use of the DISTINCT operator is explained.

7)      SELECTING CONDITIONALLY PART – 5: The concept of grouping in SQL and the use of the GROUP BY clause. A special sub section on the use of the NULL keyword in SQL is also made available.

8)      SELECTING CONDITIONALLY PART – 6.1: Primary keys and table joins as well as their practical implications and importance is highlighted in this article.

9)      SELECTING CONDITIONALLY PART – 6.2: The leftovers that I felt should be included, are described here. Basically provides an overview of good table design principles as well as a brief overview of the UNION, INTERSECT and MINUS operators.

These articles basically sum up just about everything a layperson needs to extract data from SQL based databases in anyway he/she desires.  If after reading all these articles, the reader decides that he/she should learn even more about the SQL language. That thought alone will be enough for me to consider my article series as “successful”.

I won’t claim mine to be the best tutorial series out there. This judgment is subjective and will vary from person to person. I have however found the following to be good/bad/completely avoidable sources of information. The target audience might not be beginners and some of them are created with programmers in mind.  I have included the bad as well since many of these sites might show up search pages and some of them aren’t as good as you would expect them to be.

1)      W3Schools: Provides examples for various other languages as well. Aimed at a programmer level reader. Descriptions are short, but to the point and well written.

2)      SQL Tutorials: The name itself is enough I think. A good read for a programmer, but a nightmare for a beginner. The intro section isn’t accessible at all. This site is basically an unstructured collection of blog posts. Beginners should avoid it (I think most people would avoid this one).

3)      1Keydata: Well, this one is better structured and is a good read for beginners as well. The concepts are explained in an easy way. It is also more detailed when compared to my series.  If you have read my series I think you should have no problem in understanding what is written here.

4)      SQLCourse: Another site like 3 above. Though its homepage claims also to teach MS SQL, MySQL etc, these are just links to display more ads. Having said that, this is a good SQL resource just like 1Keydata.

5)      Tizag: Now this is the site that we have been looking for. It provides tutorials for other languages like Javascript, Perl etc as well. Its SQL tutorial too is designed keeping in mind a beginner. The program SQL Express studio by Microsoft may be required to better understand the concepts on this site but this requirement is not essential.

6)      FirstSQL: Another good resource that focuses on SQL itself. Nothing else. A clean formatted site that is light to load as well and at the time of writing, displays no ads at all.

Well that sums up most of the sites I sometimes refer too. Baically, Tizag and W3Schools are the ones I would recommend. The rest are just okay.

Having said all of these, the best way to learn any language is to practice it yourself. All of us learn by making mistakes and you won’t make mistakes until you practice. To practice SQL, I would also recommend the use of the free version of the MySQL client from here.   

 

Comments

[tranmanhtan]

This is a really good tutorial for writing SQL selects.

[Jason]

Good introductory articles. I like the format of the examples.