Trait schema_connector::SchemaConnector

pub trait SchemaConnector: Send + Sync + 'static {
    // Required methods
    fn set_host(&mut self, host: Arc<dyn ConnectorHost>);
    fn set_params(&mut self, params: ConnectorParams) -> ConnectorResult<()>;
    fn set_preview_features(
        &mut self,
        preview_features: BitFlags<PreviewFeature>
    );
    fn acquire_lock(&mut self) -> BoxFuture<'_, ConnectorResult<()>>;
    fn apply_migration<'a>(
        &'a mut self,
        migration: &'a Migration
    ) -> BoxFuture<'a, ConnectorResult<u32>>;
    fn apply_script<'a>(
        &'a mut self,
        migration_name: &'a str,
        script: &'a str
    ) -> BoxFuture<'a, ConnectorResult<()>>;
    fn connector_type(&self) -> &'static str;
    fn connection_string(&self) -> Option<&str>;
    fn create_database(&mut self) -> BoxFuture<'_, ConnectorResult<String>>;
    fn db_execute(
        &mut self,
        script: String
    ) -> BoxFuture<'_, ConnectorResult<()>>;
    fn diff(&self, from: DatabaseSchema, to: DatabaseSchema) -> Migration;
    fn drop_database(&mut self) -> BoxFuture<'_, ConnectorResult<()>>;
    fn empty_database_schema(&self) -> DatabaseSchema;
    fn ensure_connection_validity(
        &mut self
    ) -> BoxFuture<'_, ConnectorResult<()>>;
    fn host(&self) -> &Arc<dyn ConnectorHost>;
    fn version(&mut self) -> BoxFuture<'_, ConnectorResult<String>>;
    fn render_script(
        &self,
        migration: &Migration,
        diagnostics: &DestructiveChangeDiagnostics
    ) -> ConnectorResult<String>;
    fn reset(
        &mut self,
        soft: bool,
        namespaces: Option<Namespaces>
    ) -> BoxFuture<'_, ConnectorResult<()>>;
    fn migration_file_extension(&self) -> &'static str;
    fn migration_len(&self, migration: &Migration) -> usize;
    fn migration_persistence(&mut self) -> &mut dyn MigrationPersistence;
    fn migration_summary(&self, migration: &Migration) -> String;
    fn destructive_change_checker(
        &mut self
    ) -> &mut dyn DestructiveChangeChecker;
    fn database_schema_from_diff_target<'a>(
        &'a mut self,
        target: DiffTarget<'a>,
        shadow_database_connection_string: Option<String>,
        namespaces: Option<Namespaces>
    ) -> BoxFuture<'a, ConnectorResult<DatabaseSchema>>;
    fn introspect<'a>(
        &'a mut self,
        ctx: &'a IntrospectionContext
    ) -> BoxFuture<'a, ConnectorResult<IntrospectionResult>>;
    fn validate_migrations<'a>(
        &'a mut self,
        _migrations: &'a [MigrationDirectory],
        namespaces: Option<Namespaces>
    ) -> BoxFuture<'a, ConnectorResult<()>>;
    fn extract_namespaces(&self, schema: &DatabaseSchema) -> Option<Namespaces>;

    // Provided methods
    fn check_database_version_compatibility(
        &self,
        _datamodel: &ValidatedSchema
    ) -> Option<DatabaseVersionIncompatibility> { ... }
    fn migration_is_empty(&self, migration: &Migration) -> bool { ... }
}

The top-level trait for connectors. This is the abstraction the schema engine core relies on to interface with different database backends.

Required Methods

fn set_host(&mut self, host: Arc<dyn ConnectorHost>)

Accept a new ConnectorHost.

fn set_params(&mut self, params: ConnectorParams) -> ConnectorResult<()>

Accept and validate new ConnectorParams. This should fail if it is called twice on the same connector.

fn set_preview_features(&mut self, preview_features: BitFlags<PreviewFeature>)

Accept a new set of enabled preview features.

fn acquire_lock(&mut self) -> BoxFuture<'_, ConnectorResult<()>>

If possible on the target connector, acquire an advisory lock, so multiple instances of migrate do not run concurrently.

fn apply_migration<'a>( &'a mut self, migration: &'a Migration ) -> BoxFuture<'a, ConnectorResult<u32>>

Applies the migration to the database. Returns the number of executed steps.

fn apply_script<'a>( &'a mut self, migration_name: &'a str, script: &'a str ) -> BoxFuture<'a, ConnectorResult<()>>

Apply a migration script to the database. The migration persistence is managed by the core.

fn connector_type(&self) -> &'static str

A string that should identify what database backend is being used. Note that this is not necessarily the connector name. The SQL connector for example can return “postgresql”, “mysql” or “sqlite”.

fn connection_string(&self) -> Option<&str>

Return the connection string that was used to initialize this connector in set_params().

fn create_database(&mut self) -> BoxFuture<'_, ConnectorResult<String>>

Create the database referenced by Prisma schema that was used to initialize the connector.

fn db_execute(&mut self, script: String) -> BoxFuture<'_, ConnectorResult<()>>

Send a command to the database directly.

fn diff(&self, from: DatabaseSchema, to: DatabaseSchema) -> Migration

Create a migration by comparing two database schemas.

fn drop_database(&mut self) -> BoxFuture<'_, ConnectorResult<()>>

Drop the database referenced by Prisma schema that was used to initialize the connector.

fn empty_database_schema(&self) -> DatabaseSchema

An empty database schema (for diffing).

fn ensure_connection_validity(&mut self) -> BoxFuture<'_, ConnectorResult<()>>

Make sure the connection to the database is established and valid. Connectors can choose to connect lazily, but this method should force them to connect.

fn host(&self) -> &Arc<dyn ConnectorHost>

Return the ConnectorHost passed with set_host.

fn version(&mut self) -> BoxFuture<'_, ConnectorResult<String>>

The version of the underlying database.

fn render_script( &self, migration: &Migration, diagnostics: &DestructiveChangeDiagnostics ) -> ConnectorResult<String>

Render the migration to a runnable script.

This should always return with Ok in normal circumstances. The result is currently only used to signal when the connector does not support rendering to a script.

fn reset( &mut self, soft: bool, namespaces: Option<Namespaces> ) -> BoxFuture<'_, ConnectorResult<()>>

Drop all database state.

Set the soft parameter to true to force a soft-reset, that is to say a reset that does not drop the database.

fn migration_file_extension(&self) -> &'static str

The file extension for generated migration files.

fn migration_len(&self, migration: &Migration) -> usize

Return the number of steps in the migration. Invariant: migration_is_empty() == true iff migration_len() == 0.

fn migration_persistence(&mut self) -> &mut dyn MigrationPersistence

See MigrationPersistence.

fn migration_summary(&self, migration: &Migration) -> String

Render a human-readable drift summary for the migration.

fn destructive_change_checker(&mut self) -> &mut dyn DestructiveChangeChecker

See DestructiveChangeChecker.

fn database_schema_from_diff_target<'a>( &'a mut self, target: DiffTarget<'a>, shadow_database_connection_string: Option<String>, namespaces: Option<Namespaces> ) -> BoxFuture<'a, ConnectorResult<DatabaseSchema>>

Read a schema for diffing. The shadow database connection string is strictly optional, you don’t need to pass it if a shadow database url was passed in params, or if it can be inferred from context, or if it isn’t necessary for the task at hand. When MultiSchema is enabled, the namespaces are required for diffing anything other than a prisma schema, because that information is otherwise unavailable.

fn introspect<'a>( &'a mut self, ctx: &'a IntrospectionContext ) -> BoxFuture<'a, ConnectorResult<IntrospectionResult>>

In-tro-spec-shon.

fn validate_migrations<'a>( &'a mut self, _migrations: &'a [MigrationDirectory], namespaces: Option<Namespaces> ) -> BoxFuture<'a, ConnectorResult<()>>

If possible, check that the passed in migrations apply cleanly.

fn extract_namespaces(&self, schema: &DatabaseSchema) -> Option<Namespaces>

Extract the namespaces from a Sql database schema (it will return None for mongodb).

Provided Methods

fn check_database_version_compatibility( &self, _datamodel: &ValidatedSchema ) -> Option<DatabaseVersionIncompatibility>

Optionally check that the features implied by the provided datamodel are all compatible with the specific database version being used.

fn migration_is_empty(&self, migration: &Migration) -> bool

Return whether the migration is empty.

Implementors