Generate an initial Prisma schema
Adopting Prisma for an existing relational database.
Prisma · Command
prisma db pull
prisma db pull introspects a database and updates the Prisma schema with models matching its current structure. It reads the connection configuration from Prisma config and supports options for selecting, printing, or replacing schema output.
How it works
The command reads the datasource connection from Prisma configuration, connects to the database, inspects its structure, converts that structure into Prisma schema models, and writes the result to the schema file. Use options to select a different schema or URL, print instead of write, or disregard the existing schema.
Syntax
prisma db pull [options]Parameters
| Name | Type | Description |
|---|---|---|
options | object | Optional command flags such as --force, --print, --config, --schema, --url, --schemas, and connector-specific options. |
Returns
Writes the introspected Prisma schema to the configured or selected schema file, or prints it to stdout when --print is used.
Key points
- Use this command to bring the database's current structure into the Prisma schema.
- It creates or updates Prisma models that represent the database schema.
- Configure the database connection in
prisma.config.tsbefore running the command. - Use
--forcewhen the introspected database should completely replace the existing schema model. - Use
--printto inspect generated schema output without directing it to the schema file. - For databases supporting multiple schemas,
--schemasselects which database schemas to inspect.
Common mistakes
- Running the command can replace the current schema, so commit or back up important manual changes first.
- For MongoDB, introspection samples data rather than reading a database schema.
Example: Introspect a database into a selected schema file
prisma db pull --schema=./prisma/schema.prismaIntrospects the configured database and writes the resulting Prisma schema to the specified schema file.
When to use it
Synchronize schema changes
A database was changed with SQL or another migration system.
Preview introspection output
You need to inspect generated schema without modifying the file.
Select schemas to introspect
A project uses multiple database schemas.
Interview questions
QWhat does prisma db pull do?
It connects to the configured database, introspects its current structure, converts that structure into Prisma models, and writes the result to the Prisma schema. The datasource URL comes from the Prisma config file.
Follow-up: How would you intentionally discard existing schema customizations? Use --force, which makes the generated schema solely from introspection and ignores the existing Prisma schema.
QWhat risk does the command pose to an existing schema?
The command can merge database changes with an existing relational Prisma schema, but it may overwrite the schema file. Important manual changes should therefore be committed or backed up before running it.
Follow-up: What should follow a successful pull in an application using Prisma Client? Run prisma generate so the client reflects the updated schema.
QWhich options are commonly useful with this command?
The basic syntax is prisma db pull [options]. Useful options include --print to send the introspected schema to standard output, --force to ignore the current schema, and --schema to choose another schema path.
Follow-up: How can the connection target be changed without editing the config? Supply --url to override the datasource URL from the Prisma config.
Related
prisma generateprisma db pushprisma db executeprisma.config.ts--force--print--schema--url