Legacy Prisma Migrate

Important! This page documents legacy Prisma Migrate (Experimental) available in version 2.12.0 and earlier. Prisma Migrate is available in version 2.13.0 and Generally Available in 2.19.0.

Legacy Prisma Migrate is a tool that lets you change your database schema, e.g. by creating new tables or adding columns to existing tables. These changes are called schema migrations. legacy Prisma Migrate is available as part of the Prisma CLI via the legacy Prisma Migrate command.

Documentation

Legacy Prisma Migrate vs the db push command

If you want to prototype or iterate on a schema design in a development environment, consider the db push command.

Legacy Prisma Migrate vs SQL migrations

Legacy Prisma Migrate is a declarative migration system, as opposed to SQL which can be considered imperative:

• SQL (imperative): Provide the individual steps to get from the current schema to the desired schema.
• legacy Prisma Migrate (declarative): Define the desired schema as a Prisma schema data model (legacy Prisma Migrate takes care of generating the necessary steps).

Here's a quick comparison. Assume you have the following scenario:

1. You need to create the User table to store user information (name, email, ...)
2. Create two new tables Post and Profile with foreign keys to User
3. Add a new column with a default value to the Post table

SQL

In SQL, you'd have to send three subsequent SQL statements to account for this scenario:

1. Create the User table to store user information (name, email, ...)

CREATE TABLE "User" (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255),
    email VARCHAR(255) NOT NULL
);

2. Create two new tables Post and Profile with foreign keys to User

CREATE TABLE "Profile" (
    id SERIAL PRIMARY KEY,
    bio TEXT NOT NULL,
    "user" integer NOT NULL UNIQUE,
    FOREIGN KEY ("user") REFERENCES "User"(id)
);
CREATE TABLE "Post" (
    id SERIAL PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    author integer NOT NULL,
    FOREIGN KEY (author) REFERENCES "User"(id)
);

3. Add a new column with a default value to the Post table

ALTER TABLE "Post"
ADD COLUMN published BOOLEAN DEFAULT false;

legacy Prisma Migrate

With legacy Prisma Migrate, you write the desired database schema in the form of a Prisma schema data model inside your Prisma schema file. To map the data model to your database schema, you then have to run these two commands:

prisma migrate save --experimental
prisma migrate up --experimental

The first command saves a new migration to the prisma/migrations directory in the file system of your project and updates the _Migration table in your database. Each time you run this command to save a new migration, it creates a dedicated directory inside of prisma/migrations for that specific migration, which will have its own README.md file containing detailed information about the migration (e.g. the generated SQL statements which will be executed when you run legacy Prisma Migrate up).

The second command executes the migration against your database.

1. Create the User table to store user information (name, email, ...)

Add the model to your Prisma schema:

model User {
  id    Int     @id @default(autoincrement())
  name  String?
  email String  @unique
}

Now run the two commands mentioned above:

prisma migrate save --experimental
prisma migrate up --experimental

2. Create two new tables Post and Profile with foreign keys to User

Add two models with relation fields to your Prisma schema:

model User {
  id      Int      @id @default(autoincrement())
  name    String?
  email   String   @unique
  posts   Post[]
  profile Profile?
}

model Profile {
  id     Int    @id @default(autoincrement())
  bio    String
  user   User   @relation(fields: [userId], references: [id])
  userId Int
}

model Post {
  id       Int    @id @default(autoincrement())
  title    String
  author   User   @relation(fields: [authorId], references: [id])
  authorId Int
}

Notice that in addition to the annotated relation fields and its relation scalar field (which represent the foreign keys), you must also specify the Prisma-level relation fields on the other side of the relation.

Now run the two commands mentioned above:

prisma migrate save --experimental
prisma migrate up --experimental

3. Add a new column with default value to the Post table

Add a field to the Post model:

model User {
  id      Int      @id @default(autoincrement())
  name    String?
  email   String   @unique
  posts   Post[]
  profile Profile?
}

model Profile {
  id     Int    @id @default(autoincrement())
  bio    String
  user   User   @relation(fields: [userId], references: [id])
  userId Int
}

model Post {
  id        Int     @id @default(autoincrement())
  title     String
  published Boolean @default(false)
  authorId  Int
  author    User    @relation(fields: [authorId], references: [id])
}

Now run the two commands mentioned above:

prisma migrate save --experimental
prisma migrate up --experimental

Supported operations

The following table shows which SQL operations are currently supported by legacy Prisma Migrate.

Note that this table assumes that the operation is also supported by the underlying database. For example, ENUM is not supported in SQLite. This means that you also can't use enum when using legacy Prisma Migrate.

Migration history

legacy Prisma Migrate stores the migration history of your project in two places:

• A directory called migrations on your file system
• A table called _Migration in your database

The migrations directory

The migrations directory stores information about the migrations that have been or will be executed against your database. You should never make any manual changes to the files in migrations. The only way to change the content of this directory should be using the legacy Prisma Migrate save command.

The migrations directory should be checked into version control (e.g. Git).

The _Migration table

The _Migration table additionally stores information about each migration that was ever executed against the database by legacy Prisma Migrate.

Typical workflow

With legacy Prisma Migrate, the workflow looks slightly different:

1. Manually adjust your Prisma schema data model
2. Migrate your database using the legacy Prisma Migrate CLI commands
3. (Re-)generate Prisma Client
4. Use Prisma Client in your application code to access your database

Troubleshooting

Since legacy Prisma Migrate is currently Experimental, you might end up in a state where the migrations directory and/or the _Migrations table are out of sync with the actual state of the database. In these cases, it often helps to "reset" legacy Prisma Migrate by deleting the migrations folder and deleting all entries from the _Migration table.

Delete the migrations directory

rm -rf migrations

Delete all entries from the _Migration table

TRUNCATE _Migration;

CLI Reference

Warning: The migrate command is still considered Experimental. As such, there are no guarantees about API stability or production-readiness. Access to this command is provided for evaluation and experimentation. To access Experimental commands, you must add the --experimental flag.

The migrate command creates and manages database migrations. It can be used to create, apply, and rollback database schema updates in a controlled manner.

The migrate command includes a number of subcommands to specify the desired action.

migrate save

Saves a migration that defines the steps necessary to update your current schema.

Prerequisites

Before using the migrate save command, you must define a valid datasource within your schema.prisma file.

For example, the following datasource defines a SQLite database file within the current directory:

datasource db {
  provider = "sqlite"
  url      = "file:my-database.db"
}

Options

The migrate save command recognizes the following options to modify its behavior:

Generated Assets

The migrate save command generates the following directories and files as necessary:

• migrations: A directory within the current project to store migrations. This directory will be created if it does not exist.
• migrations/migrate.lock: A lock file created specifying the current migration applied to the database. This file will be created if it does not exist.
• migrations/<migration>: A directory for a specific migration. The migration name is derived from the timestamp when it was created followed by a hyphen and the migration name provided by the user.
• migrations/<migration>/README.md: A human-readable description of the migration including metadata like when the migration was created and by who, a list of the actual migration changes and a diff of the changes that are made to the schema.prisma file.
• migrations/<migration>/schema.prisma: The schema that will be created if the migration is applied to the project.
• migrations/<migration>/steps.json: An alternative representation of the migration steps that will be applied.

Examples

Create a new migration

prisma migrate save --experimental

The command will prompt you for a name for the migration since one was not provided on the command line. After creating the migration, the contents of the generated schema.prisma file are displayed.

Create a migration with a specific name

prisma migrate save --name "First migration" --experimental

Create the database if it does not already exist

prisma migrate save --create-db --experimental

Preview the migration that would be created by running the migrate save command

prisma migrate save --preview --experimental

migrate up

Migrate the database up to a specific state.

Prerequisites

Before using the migrate up command, you must define a valid datasource within your schema.prisma file.

For example, the following datasource defines a SQLite database file within the current directory:

datasource db {
  provider = "sqlite"
  url      = "file:my-database.db"
}

Arguments

The point to migrate the database up to can be defined in any of the following three ways:

Options

Additionally, the following options modify the behavior of the migrate up command:

Examples

Migrate the database up to the latest available migration

prisma migrate up --experimental

Apply the next two migrations to the database

prisma migrate up 2 --experimental

Apply all migrations necessary up to and including a migration by name

prisma migrate up "First migration" --experimental

Apply all migrations necessary up to and including a migration by timestamp

prisma migrate up 20200223181448 --experimental

Create the database if it does not already exist before applying the migrations

prisma migrate up --create-db --experimental

Preview the migration that would be applied by running the migrate up command

prisma migrate up --preview --experimental

migrate down

Migrate the database down to a specific state.

Prerequisites

Before using the migrate down command, you must define a valid datasource within your schema.prisma file.

For example, the following datasource defines a SQLite database file within the current directory:

datasource db {
  provider = "sqlite"
  url      = "file:my-database.db"
}

Arguments

The point to migrate back to can be defined in any of the following three ways:

Options

Additionally, the following options modify the behavior of the migrate down command:

Examples

Migrate the database backwards by a single migration

prisma migrate down --experimental

Migrate the database backwards by two migrations

prisma migrate down 2 --experimental

Migrate backwards through all migrations up to and including a migration by name

prisma migrate down "First migration" --experimental

Migrate backwards through all migrations up to and including a migration by timestamp

prisma migrate down 20200223181448 --experimental

Preview the migration that would be applied by running the migrate down command

prisma migrate down --preview --experimental