AddCriteria Simplifies SQL Queries
AddCriteria is a short function that simplifies the code needed to produce a SQL query from a set of optional criteria posted by a user.
Advanced SQL Techniques - Part 1: Analyzing Duplicate Record
This article offers an analysis of Structured Query Language
(SQL) and presents techniques that can be used in building SQL
statements. The cases presented here are intended for certain
circumstances, but they can be applied to many situations. Each
article in this four-part series will address one case.
Data Definition Language
GUI-based database management tools are great, but it's also important to understand the broad strokes of directly manipulating database structure. This article describes how to use SQL to define the database, its component tables, and other artifacts.
Interactive SQL Tutorial
Structured Query Language is the standard language used to communicate with database software. SQL is a complex and powerful language and a full treatment of it is outside the scope of this article, however it will help you to understand basic SQL commands, basics of relational databases. You can even execute sample SQL queries and get results right on the Web page.
Interactive/Online SQL Tutorial with SQL live practive database
This unique introductory SQL tutorial not only provides easy-to-understand SQL instructions, but it allows you to practice what you learn using the on-line SQL interpreter. You will receive immediate results after submitting your SQL commands.
Introducing SQL Sets
Because SQL is based on relational algebra, it should come as no surprise that the standard contains several set-oriented operators. In that spirit, it's time we take a look at the UNION operator.
JOINed at the Hip
The JOIN clause is probably one of the most used -- as well as one of the most confusing -- facets of SQL. This article introduces the JOIN clause.
Online SQL tutorial
This unique introductory SQL tutorial not only provides easy-to-understand SQL instructions, but it allows you to practice what you learn using the on-line SQL interpreter. You will receive immediate results after submitting your SQL commands. You will be able to create your own unique tables as well as perform selects, inserts, updates, deletes, and drops on your tables. This SQL tutorial currently supports a subset of ANSI SQL. The basics of each SQL command will be covered in this introductory tutorial. Unless otherwise stated, the interpreter will support everything covered in this course.
If you're already familar with the basics of SQL, you can still use this as a refresher, and practice some SQL statements.
Selects in Inserts
One thing you often get with a PHP Project is a big SQL file with a lot of inserts and create statements. Nothing wrong with that. But often people use the ID from an earlier insert directly in another statement. Nothing wrong with that except that readability sinks to zero, especially for someone trying to figure out what is going on.
Self-Inflicted SQL
This article looks at the "self-join," a tool that is particularly useful in certain situations, such as when you have a normalized database table that needs to be flattened.
SQL Data Types
Most database products support ANSI-SQL for manipulating data, but there is far more variance in the details of how DDL is implemented. This article discusses data types for different SQL platforms.
SQL In Simple English - Part 2
This is the second article in this series. If you liked the first one, you will definitely like this one too. This article mainly deals with SQL Joins and SQL subqueries. Both of these are extremely useful SQL constructs and should be learnt by all beginners.
SQL In Simple English - Part I
I have found that many articles found on the net are good and detailed but they are not really friendly to novice programmers. In my article the topic is presented as a Q&A session. Most of the questions are the ones that most novices would like to ask. And the Answers are present in very simple language. This approach is excellent and readers who aren't familiar with the technology seem to understand the article in 1 reading itself. I have kept the article totally language neutral. Hence programmers using any language and who want to do database programming will find it useful.
SQL Subqueries
Subqueries are extremely useful in web-based database applications where you need to combine two queries and manually put them together to achieve a desired result. Subqueries allow SQL to do all of the heavy lifting!
SQL Tutorial
This SQL Tutorial site is aimed to teach beginners the building blocks of SQL. Vendors have also developed their versions of SQL such as Transact-SQL and PL/SQL. Any experienced webmaster knows that SQL is the true engine for interacting with the database behind scripting languages such as ASP, perl, or PHP. The Microsoft .Net platform also relies heavily on SQL...
SQL: Nulls: Nothing to Worry About
Called null values in the ISO SQL standard, nulls are anything but values. Nulls are markers indicating the complete lack of a value. They lead to three-valued logic, which is confusing to work with, and that confusion often leads the unwary down the path of writing SELECT statements that return wrong results. This article highlights some of the pitfalls you'll encounter and gives advice for avoiding them.
SQL:Cursor Example
Database cursors allow you to breakdown and process more
information within the same batch statement. This example
demonstrates the basic framework to create a database cursor
and tailor it to your needs.
SQLProcess - A Powerful SQL Statement Generator
This article demonstrates how to use his SQLProcess application, which is a very powerful SQL statement generator! With a single page, you can update, insert, delete, and view records from a database.
Summarizing data with SQL (Structured Query Language)
This article provides a brief SQL How-to on how to summarize data. Most of the examples we provide will be based on the ANSI-SQL 92 standard. Some examples will show features specific to SQL Server 7.
TSQL : Select Case
Use the Select Case statement to shape your results. This
example will show you how to use CASE keyword to return the
results that you need. Multiple examples are shown.
Types of JOINs
A look at what's going on behind the scenes when you perform a "join" in MySQL. This article uses the cross join as an example of how joins work in general.
Using SELECT to retrieve data
This tutorial deeply covers the SELECT statement of the T-SQL/SQL language. Starts from the basics - how to retrieve the values inside a column to ordering data, selecting multiple columns and then tables, joining them...
Using the Group By Clause
While most developers are familiar with the basic SQL syntax for constructing SELECT statements, many folks have rarely, if ever, used one of the more powerful clauses of the SELECT statement: Group By.
What's the Big Deal about SQL?
SQL, the Structured English Query Language, is a standard for building relational databases. In this short introduction explains relational databases and offers a history of the development and implementation of SQL.
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