Missing Data
When we don't have all the information needed to model data, we often use NULL. However, that causes other issues.
2021-04-12
2,779 reads
Joe Celko
Mathematicians and SQL
Georg Ferdinand Ludwig Philipp Cantor is considered the creator of set theory, and his theories are the basis for the naïve set theory you learned in school. But there are lots of other mathematicians you should know, such as Hilbert, Frege, Russell, Zermelo and Dedekind. They made a lot of contributions, too. Hilbert Hilbert is […]
2021-01-19
5,634 reads
Data Element Names and Scoping Rules in SQL
How you name data elements in databases and applications programs has often been a matter of personal taste. Decades ago, when I worked for state government, there is a COBOL programmer who would pick a theme for his programs. The paragraphs and variables would be named based on the current theme. One of his programs […]
2021-01-11
2,185 reads
Stairway to Database Design Level 8: Cursors
This final level to the first landing completes the basics of a SQL database, by explaining what cursors are and why you should never use them.
2020-11-18 (first published: 2011-11-02)
11,779 reads
2020-10-12
2,002 reads
Stairway to Data, Level 4: Temporal Data
Joe Celko tackles the most difficult of all the types of data handled by SQL, temporal data, and explains how to avoid the commonest traps for the unwary programmer
2020-07-08 (first published: 2011-06-15)
11,248 reads
Stairway to Database Design Level 6: Procedure Bodies
Having covered the procedure headers in SQL Server in the previous level, Joe tackles the subject of the contents of stored procedures. In this level, he outlines limitations of TSQL as a procedural language, and what you need to bear in mind when deciding how to use them.
2019-04-03 (first published: 2011-09-21)
13,545 reads
Stairway to Data, Level 1: The Basics
A great deal of the confusion that occurs when a database application is developed comes from a poor understanding of the basics of data. Here, Joe Celko gives a broad coverage of the difficulties you're likely to meet when handling data in databases.
2019-03-26 (first published: 2011-05-12)
20,733 reads
Stairway to Data, Level 2: Numerics
A confusion about the nature of numbers can lead to a number of problems in database applications. Joe Celko gives a simple guide to the subject
2019-03-26 (first published: 2011-05-18)
12,396 reads
Stairway to Data, Level 3: Strings
Character-handling in SQL is not particularly straightforward, and confusion about collation and character encoding is a common cause of problems with searching, joining, and sorting.
2019-03-26 (first published: 2011-06-01)
9,543 reads
Blogs
Webinar: Navigating the Database Landscape in 2026
By Steve Jones
For a number of years, we’ve produced the State of the Database Landscape report,...
Claude AI Convinced Me Not to Build an iPad App
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I coach volleyball and I do a lot of stat stuff on paper. I...
A New Word: Dolorblindness
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dolorblindness – n. the frustration that you’ll never be able to understand another person’s...
Forums
SSMS 22 Latest Update Crashing
Hi all, I've just had to roll back my SSMS 22 version from 22.3.0,...
Transactional Replication setup issue
Hi! I've been banging my head against the wall for 2 days now trying...
The Power of Data and Privacy
Comments posted to this topic are about the item The Power of Data and...
Question of the Day
What's the Date?
In SQL Server 2025, there is a new function that returns the current date without the time. What is it?
See possible answers