On the SitePoint PHP blog Zach Wallace shares more database wisdom with his readers introducing three more JOINs you should know in your development work.

There are many ways to JOIN data from two database tables and filter the information you require. Craig Buckler wrote a popular piece on understanding JOINs; namely INNER, LEFT, RIGHT, and FULL OUTER. This article is an extension of that one.

He starts with the data he'll be working with: customers and books, linked by a book_id column. He then quickly reviews some of the joins already discussed in the previous article (LEFT, RIGHT, OUTER, INNER) before getting into the newer, more powerful types:

• LEFT JOIN with Exclusion
• RIGHT JOIN with Exclusion
• OUTER JOIN with Exclusions

He finishes the post with a few other thoughts about using WHERE clauses in JOINs, the CROSS JOIN and how the JOINs relate to each other in MySQL.

In a recent post to his blog Anna Filina looks at internationalization in Doctrine and how Symfony auto-builds things to take care of it for you.

If you use Doctrine, then you probably know how lazy loading can hurt your performance. I carefully craft every query to everything that I need in one shot, but only what I need. One thing that evaded me at first was the i18n part. I am pleased with the way Doctrine + symfony magically creates all my models and database tables with i18n support.

She talks a bit about the internationalization (i18n) support is put into the schema.yml file and the bit of confusion she had over how to handle a left join using its structure. The key lies in the Translation relationships.