Entity Framework Core Interview Question #84
What is an idempotent migration script?
Migrations, Database Schema & Data Management Mid-Level Intermediate
Quick Interview Answer
An idempotent EF Core migration script contains logic that applies only migrations that have not already been recorded as applied. This allows the same script to be used against databases that may be at different known migration levels.
Detailed Explanation
An idempotent EF Core migration script contains logic that applies only migrations that have not already been recorded as applied. This allows the same script to be used against databases that may be at different known migration levels.
It is useful in some deployment pipelines, but the script still requires review because individual schema operations can have locking, performance, or data-loss consequences.
Idempotence of migration selection does not mean every business data transformation is automatically safe to repeat.
Code Example
dotnet ef migrations script --idempotent -o migration.sql