What it is, why it happens, how it breaks your schema, and how to fix it for good.
You are designing a database schema, tables are coming together nicely, foreign keys are in place, and then suddenly, you can't insert a single row without violating a constraint. Every table is waiting on another. You are stuck in a loop. That, right there, is circular injection, one of the sneakiest traps in relational database design.
This article breaks down what circular injection (also called a circular dependency or circular reference) is, shows you real examples of how it appears, explains why it is a problem, and walks you through the proven patterns to resolve it.
A circular dependency is when Table A depends on Table B, which depends on Table C… which depends right back on Table A. Nobody can go first.
What is Circular Injection
