Linux Today: Linux News On Internet Time.

More on LinuxToday

The Basics of SQL Joins in MySQL

Mar 30, 2010, 18:33 (0 Talkback[s])
(Other stories by Jason Gilmore)


Re-Imagining Linux Platforms to Meet the Needs of Cloud Service Providers

"When making your first forays into relational database development, you can use simple SQL statements to mine your data easily enough. However, as your data grows in both size and breadth, you'll need to begin employing more sophisticated strategies for exploiting increasingly complex data relations. After all, pulling data from a single table is easy, but what if you need to query for data spanning three, four, or even eight different tables?

"Retrieving interrelated data stored within multiple tables is most effectively accomplished using a SQL JOIN clause, of which there are several variants. The JOIN clause relies upon related fields found in two tables to determine the commonality of the data stored within each, producing a data set that you can then easily save or further manipulate.

"In this article, I introduce three of the most commonly used JOIN variants: the INNER JOIN, OUTER JOIN, and SELF JOIN, and provides MySQL examples for using them. Although these examples will be MySQL-specific, you'll be able to use what you learn here within most -- if not all -- other relational database solutions."

Complete Story

Related Stories: