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
2,380 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
5,313 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
1,631 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)
11,250 reads
2020-10-12
1,898 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)
10,895 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)
12,984 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.
2019-02-06 (first published: 2011-05-12)
19,611 reads
Stairway to Database Design Level 9: Normalization
In the final step of Database Design, Joe Celko gives a simple but effective explanation of the normalization process and why it is important.
2018-02-21 (first published: 2011-11-11)
14,002 reads
Stairway to Database Design Level 7: Triggers
In levels one to four, we built the tables, base and virtual, of a schema. Levels five and six dealt with stored procedures. This level deals with a feature you need to avoid as much as possible; this is article is on Triggers.
2018-01-24 (first published: 2011-09-30)
11,539 reads
Blogs
Be careful with table updates
The dire warning in the subject line is not meant to scare you. Rather,...
Daily Coping 1 Dec 2021
By Steve Jones
I started to add a daily coping tip to the SQLServerCentral newsletter and to...
Building a pacemaker cluster to deploy a SQL Server availability group in Azure
There are new Ubuntu Pro 20.04 images available in the Azure marketplace with SQL...
Forums
Help with Column Visibility Expressions
I have a parameter in my report labeled as PaySource. PaySource has 3 values...
SQL Server and CloudStrike
Has anyone had issues with CloudStrike Anti-Virus on their SQL Servers? I've had a...
Table Date field format
I created a date field [Datte] in SQL v2008. I then link with MS...
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