How to mix values from the current rows with values from previous or preceding rows.
How to avoid duplicate sub queries with using the SQL-99 clause WITH.
Every needed a table with some data to run your tests? Check this article for a simple query to create a table with random text and dates.
You sure have a backup when running an Oracle database but sometimes it takes a while to restore a single table or even a single row. Oracle comes with a handy feature called "Flashback" which allows you to run a query on a table state from the past.
Ever wondered what Oracle function you can use? There's a data dictionary telling you about every available function including some additional information.
Having a list of tables in a database can help you to get a picture of what's there. Here's how you can do that.
Ever wanted to group a number of rows into a single row as a list? This recipe shows you how to do that.
Have you ever tried to limit the number of rows in combination with an order by and didn't get the expected result? Here's why and of course the correct way!
In some rare cases you won't want to normalize a table but simply add a list of values in a single cell. This is what VARRAY types are good for.