Foreign Keys

Database Design & Metadata

Test If Your Database Has Foreign Keys Or Is It Full of Loners (Metric + Test Queries)

Databases should but many don't have foreign key constraints. Does your database have them? To what extent? Here is a me...

Piotr Kononow 7 min read

Database Design & Metadata

Don't Most Databases Have Foreign Key Constraints? [Research data + Poll]

Results of my research of existence of foreign key constraints in 40 example databases.

Piotr Kononow 5 min read

Application Metadata

Major Applications Do Not Use Foreign Key Constraints In Their Databases (Oracle, Microsoft, SAP)

My research revealed that most major ERP and CRM applications do not use foreign key constraints in their databases.

Piotr Kononow 2 min read

Database Design & Metadata

9 reasons why there are no foreign keys constraints in your database (referential integrity checks)

A compilation of reasons why databases don't have defined foreign keys.

Piotr Kononow 6 min read

Database Design & Metadata

2 Common SQL Join Traps (with Test Queries)

There are 2 very common traps (with serious consequences) you can easily fall into while joining tables in an SQL query....

Piotr Kononow 4 min read