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 data model (legacy Prisma Migrate takes care of generating the necessary steps).
Here's a quick comparison. Assume you have the following scenario:
- You need to create the
User
table to store user information (name, email, ...) - Create two new tables
Post
andProfile
with foreign keys toUser
- 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 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 @uniqueposts Post[]profile Profile?}model Profile {id Int @id @default(autoincrement())bio Stringuser User @relation(fields: [userId], references: [id])userId Int}model Post {id Int @id @default(autoincrement())title Stringauthor 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 @uniqueposts Post[]profile Profile?}model Profile {id Int @id @default(autoincrement())bio Stringuser User @relation(fields: [userId], references: [id])userId Int}model Post {id Int @id @default(autoincrement())title Stringpublished Boolean @default(false)authorId Intauthor 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.
Operation | SQL | Supported |
---|---|---|
Create a new table | CREATE TABLE | ✔️ |
Rename an existing table | ALTER TABLE + RENAME | No |
Delete an existing table | DROP TABLE | ✔️ |
Add a column to an existing table | ALTER TABLE + ADD COLUMN | ✔️ |
Rename an existing column | ALTER TABLE + RENAME COLUMN | No |
Delete an existing column | ALTER TABLE + DROP COLUMN | ✔️ |
Set primary keys (IDs) | PRIMARY KEY | ✔️ |
Define relations (foreign keys) | FOREIGN KEY + REFERENCES | ✔️ |
Make columns optional/required | NOT NULL | ✔️ |
Set unique constraints | UNIQUE | ✔️ |
Set default values | DEFAULT | ✔️ |
Define enums | ENUM | ✔️ |
Create indexes | CREATE INDEX | ✔️ |
Cascading deletes | ON DELETE | No (workaround: manually add in SQL and introspect) |
Cascading updates | ON UPDATE | No |
Data validation | CHECK | No (workaround) |
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:
- Manually adjust your Prisma data model
- Migrate your database using the
legacy Prisma Migrate
CLI commands - (Re-)generate Prisma Client
- 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:
Option | Required | Description | Default |
---|---|---|---|
--experimental | Yes | Enables use of Experimental commands. | |
-n , --name | No | The name of the migration. If not provided, migrate save will prompt you for a name. | Timestamp 20200618145356 |
-c , --create-db | No | Create the database if it does not exist. | |
-p , --preview | No | Preview the migration that would be created without writing any changes to the filesystem. | |
--schema | No | Specifies the path to the desired schema.prisma file to be processed instead of the default path. Both absolute and relative paths are supported. | ./schema.prisma , ./prisma/schema.prisma |
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 theschema.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:
Argument | Required | Description | Default |
---|---|---|---|
increment | No | Specifies the number of forward migrations to apply. | latest |
name | No | Specifies where to migrate to using the name of the final migration to apply. | latest |
timestamp | No | Specifies where to migrate to using the timestamp of the final migration to apply. | latest |
Options
Additionally, the following options modify the behavior of the migrate up
command:
Option | Required | Description | Default |
---|---|---|---|
--experimental | Yes | Enables use of Experimental commands | |
-c , --create-db | No | Create the database if it does not exist. | |
-p , --preview | No | Preview the migration that would be created without writing any changes to the filesystem. | |
--schema | No | Specifies the path to the desired schema.prisma file to be processed instead of the default path. Both absolute and relative paths are supported. | ./schema.prisma , ./prisma/schema.prisma |
--auto-approve | No | Skip interactive approval before migrating. |
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:
Argument | Required | Description | Default |
---|---|---|---|
decrement | No | Specifies the number of backwards migrations to apply. | 1 |
name | No | Specifies where to migrate back to using the name of the final migration to apply. | |
timestamp | No | Specifies where to migrate back to using the timestamp of the final migration to apply. |
Options
Additionally, the following options modify the behavior of the migrate down
command:
Option | Required | Description | Default |
---|---|---|---|
--experimental | Yes | Enables use of Experimental commands | |
-p , --preview | No | Preview the migration that would be created without writing any changes to the filesystem. | |
--schema | No | Specifies the path to the desired schema.prisma file to be processed instead of the default path. Both absolute and relative paths are supported. | ./schema.prisma , ./prisma/schema.prisma |
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