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Oracle PL/SQL (Procedural Language/Structured Query Language) resources, news, and support articles.

MySQL bind-address

While I try to keep things simple, sometimes eliminating options and explanations comes back to haunt me. After posting how to open a Fedora firewall port for a LAMP stack, somebody got trapped by my instructions for installing MySQL on Fedora. They got stuck because they had the following setting in their my.cnf file:

Open Fedora Port 80

After installing the LAMP stack on Fedora, you need to open port 80 in the Firewall to access the PHP programs on the Fedora instance from external servers. You can open a firewall port by launching the firewall-config application as the root user with the following syntax:

Fedora Install LAMP

My students wanted an extra credit assignment, so I thought a LAMP configuration and test would be appropriate. The only problem was I hadn’t added it to their course VMware instance. So, here are the instructions to install Apache2, PHP, and MySQLi for a complete LAMP stack.

Tweaking the Weekly Quizzes at the PL/SQL Challenge

We've decided a couple of things:

  1. Enough with the really dull names as in "Weekly SQL Quiz".
  2. It's time to start up Deja Vu quizzes for SQL, Database Design, and Logic.
So starting on 4 April 2015 (just shy of the fifth anniversary of the PL/SQL Challenge)....
SQL Quizzes
We will rename and continue the weekly SQL quiz as Select from SQL.

And we will add a Deja Vu SQL quiz.

Lowercase Table Names

A student posed the question about why table names are case sensitive. That’s because case insensitive table names are the default installation, as qualified in the MySQL documentation. You can verify that with the following query:

Join Tables on Date Ranges

A recent question on the OTN SQL forum asked how best to join two tables related by ID and date range, in order to insert one row per date into a data warehouse. One solution was to expand the data from each table, creating one row per date, then join on date. I think it's more efficient to join on date range, then expand.

Results of 2014 PL/SQL Championship

You will find below the rankings for the 2014 PL/SQL Championship; the number next to the player's name is the number of times that player has participated in a championship (you will see "1" for all players, since this was the first annual PL/SQL championship).

Congratulations first and foremost to our top-ranked players:

1st Place: mentzel.iudith of Israel

PostgreSQL Types

PostgreSQL like Oracle supports record data types but unlike Oracle, PostgreSQL doesn’t support collections of record data types. Here’s an example of how to define a PostgreSQL composite data type, and how to use it as a column’s data type.

PostgreSQL Auto Increment

PostgreSQL’s approach to automatic numbering, is simpler than Oracle, MySQL, and Microsoft SQL Server. For example, you have a two-step process with Oracle, MySQL, and Microsoft SQL Server. First, you create an Oracle table with the GENERATED AS IDENTITY clause, a MySQL table with the AUTO_INCREMENT clause, and a Microsoft SQL Server table with the IDENTITY(1,1) clause. Then, you need to write an INSERT statement like:

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