1. When you run

prisma migrate dev

, it replays the existing migration history in the shadow database in order to detect schema drift (edited or deleted migration file, or a manual changes to the database schema) 2. Applies pending migrations to the shadow database (for example, new migrations created by colleagues) 3. Generates a new migration from any changes you made to the Prisma schema before running

migrate dev

4. Applies all unapplied migrations to the development database and updates the

_prisma_migrations

table 5. Triggers the generation of artifacts (for example, the Prisma Client) The

migrate dev

command will prompt you to reset the database in the following scenarios: • Migration history conflicts caused by modified or missing migrations • The database schema has drifted away from the end-state of the migration history See more details in the docs.

Hi @Peter, I have verified by adding a CHECK constraint, I can execute

npx prisma migrate dev --create-only

to create a migration file without applying it. I edited the file to add a CHECK constraint. Example:

ALTER TABLE "User"
ADD CONSTRAINT "image" 
CHECK (
	image IS NULL
);

After adding the check constraint, I executed

npx prisma migrate dev

to apply the check constraint. In this case the diff was not detected, if you add a CHECK constraint. In case of

index

diff gets detected in some cases as described in this Github Issue.

You're welcome.