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SQL Data Types Publish Date: Sep. 13, 2001
Most database products support ANSI-SQL for manipulating data, but there is far more variance in the details of how DDL is implemented. John Paul Ashenfelter discusses data types for different SQL platforms.
Working With Tables Publish Date: Sep. 6, 2001
In the last aboutSQL column , John Paul Ashenfelter introduced the Data Definition Language (DDL) and how to create database containers. This week, he moves on to creating tables and populating them with data.
Data Definition Language Publish Date: Aug. 30, 2001
GUI-based database management tools are great, but it's also important to understand the broad strokes of directly manipulating database structure. In this week's aboutSQL , John Paul Ashenfelter describes how to use SQL to define the database, its component tables, and other artifacts.
Introducing SQL Sets Publish Date: Aug. 2, 2001
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.
SQL Subqueries Publish Date: Jul. 26, 2001
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!
Self-Inflicted SQL Publish Date: Jul. 12, 2001
This week, John Paul Ashenfelter 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.
The Outer Limits of SQL JOINs Publish Date: Jun. 27, 2001
In the last column, John Paul Ashenfelter showed you how to use inner joins and cross joins. This week he tackles outer joins.
Types of JOINs Publish Date: Jun. 15, 2001
A look at what's going on behind the scenes when you perform a "join" in MySQL. John Paul Ashenfelter uses the cross join as an example of how joins work in general.
More on JOINS Publish Date: Jun. 1, 2001
The exploration into JOIN statements continues with a look at INNER JOIN, the most commonly used SQL join.
JOINed at the Hip Publish Date: May. 24, 2001
The JOIN clause is probably one of the most used -- as well as one of the most confusing -- facets of SQL. John Paul Ashenfelter introduces the JOIN clause.
Types of Relationships Publish Date: Mar. 20, 2001
How well are your database tables communicating with one another? This week John Paul discusses three key relationships: one to one, one to many, and many to many.
Good Relations Publish Date: Mar. 13, 2001
John Paul Ashenfelter looks at how keys are used to construct relationships between tables in a relational database.
The "Key" to Good SQL Publish Date: Mar. 6, 2001
Database "keys" help eliminate confusion among records. Here's how to best incorporate these essential identifiers in your database.
Group By Publish Date: Feb. 23, 2001
The GROUP BY clause is the next step after mastering ORDER BY. John Paul Ashenfelter shows you how to combine database records into a single record to calculate an aggregate function.
Controlling Data Display with ORDER BY Publish Date: Feb. 13, 2001
This week, John Paul Ashenfelter revisits the ORDER BY clause to help you control the display of your MySQL data.
