Joe Celko is one of the most widely read of all writers about SQL, and was the winner of the DBMS Magazine Reader's Choice Award four consecutive years. He is an independent consultant living in Austin, TX. He has taught SQL in the US, UK, the Nordic countries, South America and Africa.
He served 10 years on ANSI/ISO SQL Standards Committee and contributed to the SQL-89 and SQL-92 Standards.
He has written over 800 columns in the computer trade and academic press, mostly dealing with data and databases. He is the author of eight books on SQL for Morgan-Kaufmann, including the best selling SQL FOR SMARTIES.
Joe is a well-known figure on Newsgroups and Forums, and he is famous for his his dry wit. He is also interested in Science Fiction.
To prevent data change anomalies, a database should be normalized. Did you know that there are 10 normal forms? In this article, Joe Celko reviews normalizing databases including commonly used normal forms.… Read more
Dr. Codd proposed the normalization rules we used to design databases, but did you know that he also came up with rules that vendors must meet to call their products relational database systems? In this article, Joe Celko explains the thirteen RDBMS rules.… Read more
The logic for referential integrity can be implemented in application code, but to make sure that it is enforced, include foreign key constraints in the database design instead. In this article, Joe Celko talks about the history of references in SQL and the options available today. … Read more
Understanding scoping rules is a basic skill for developers. In this article, Joe Celko gives a bit of the history of scoping in early programming languages and shows how scoping applies to SQL queries as well. … Read more
There are those who argue that time doesn’t really exist; it’s just an illusion. That debate won’t keep you from storing and manipulating dates and time in SQL Server. In this article, Joe Celko discusses some of the many ways that SQL Server treats temporal data types.… Read more
Whether or not to have NULLable columns in a table can be a religious debate, and how missing data is represented should be carefully considered during database design. In this article, Joe Celko considers the ways that SQL Server handles NULLs in several situations. … Read more