On storing objects in tables
In this article, I want to demonstrate how to achieve a parent-child relationship with PL/SQL objects stored in tables.
View ArticleOn max and group by
This article presents three different ways to group a select's result set and find each group's record whose column is max().
View ArticleOn an integer not always being an integer
Until recently, I believed that an integer is a number that can only store whole numbers. Unfortunately, that is not always the case with Oracle.
View ArticleOn a member function calling a member procedure
I was very surprised when I tried to call a member procedure from a member function because I got a PLS-00363: expression 'SELF' cannot be used as an assignment. Why this is and how to avoid this.
View ArticleOn solving a sudoku with Oracle
A is a puzzle that consists of a 9x9 grid whose cells contain numbers between 1 and 9. At the beginning, only a few of these celles are filled in, and it's the solver's task to fill in every cell...
View ArticleOn improving a better describe
Recently, I presented . Now, sent me an email with some improvements.
View ArticleOn mixing outer joins with inner joins
A few ways to combine an outer joins with an inner join in a select statement.
View ArticleOn reading blobs from and writing blobs to a file
Writing blobs to a file and reading them from a file is too tedious for my liking. Therefore, I have written a package to faciliate these tasks. It comes with a procedure (to_file) which writes a blob...
View ArticleOn creating bitmaps with pure PL/SQL
Out of idle curiosity, I wanted to know if it is possible to create bitmaps (BMPs) with pure PL/SQL alone. And it is!
View ArticleOn identifiying "periods of activity"
I have a table that logs what items were bought at what time from a vending machine. Now, I want to find periods of activity on this machine.
View ArticleOn a table's first five rows
Using rownum to select the first n rows does not always return the same records
View ArticleOn triggers, sequences, autonumbers and failing inserts
Is a sequence increased when I use a trigger and a sequence to generate autonumbers and an insert fails?
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