docs/1.14/04-Reference/02-Service-Configuration/03-Data-Model/02-Migrations.md
When using Prisma you can connect databases in two different modes:
multi-tenant When a database is configured to operate in multi-tenancy mode, you can use it to deploy as many Prisma services as you want. For each Prisma service you deploy, a new database schema is created. This way your services are fully isolated. The database schema name is based on the name and stage of your service. This was the only way to use Prisma before the 1.8 release.
single-tenant To use prisma with an existing database, you must configure it in single-tenancy mode by specifying the name of the schema that contains your data. When a database is operating in single-tenancy mode, all Prisma services configured for the database will use the same database schema.
Currently it is only possible to configure a single database and it has to be called default. In the future it will be possible to configure multiple named databases and use them from the same service.
Migrations
note: currently Prisma can only migrate databases operating in multi-tenancy mode. This will be improved in the future
If you are using Prisma together with a database that is controlled by an existing application, you probably do not want Prisma to migrate the database structure. You can disable Prisma migrations by setting the migrations configuration option to false:
port: 4466
databases:
default:
connector: postgres
host: localhost
port: 5432
user: root
password: prisma
database: prisma
schema: my_schema
migrations: false
Read more about server configuration options in server configuration
When migrations are disabled, deploying your service will not migrate the underlying database. Instead it will change the shape of the generated GraphQL API. Changing your data model allows you to hide tables, rename columns and much more. See introspection for more details.
Migrations are enabled by default. To make it more explicit you can set the migrations key to true.
When migrations is enabled, deploying a service will actively migrate the underlying database. Read more about how this works in the data modelling chapter.