prefect.server.database.interface

Classes

DBSingleton ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L21" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Ensures that only one database interface is created per unique key

PrefectDBInterface ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L55" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

An interface for backend-specific SqlAlchemy actions and ORM models.

The REST API can be configured to run against different databases in order maintain performance at different scales. This interface integrates database- and dialect- specific configuration into a unified interface that the orchestration engine runs against.

Methods:

Agent ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L270" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Agent(self) -> type[orm_models.Agent]

An agent model

Artifact ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L205" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Artifact(self) -> type[orm_models.Artifact]

An artifact orm model

ArtifactCollection ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L210" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

ArtifactCollection(self) -> type[orm_models.ArtifactCollection]

An artifact collection orm model

Automation ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L315" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Automation(self) -> type[orm_models.Automation]

An automation model

AutomationBucket ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L320" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

AutomationBucket(self) -> type[orm_models.AutomationBucket]

An automation bucket model

AutomationEventFollower ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L337" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

AutomationEventFollower(self) -> type[orm_models.AutomationEventFollower]

A model capturing one event following another event

AutomationRelatedResource ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L325" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

AutomationRelatedResource(self) -> type[orm_models.AutomationRelatedResource]

An automation related resource model

Base ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L175" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Base(self) -> type[orm_models.Base]

Base class for orm models

BlockDocument ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L290" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

BlockDocument(self) -> type[orm_models.BlockDocument]

A block document model

BlockDocumentReference ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L295" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

BlockDocumentReference(self) -> type[orm_models.BlockDocumentReference]

A block document reference model

BlockSchema ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L280" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

BlockSchema(self) -> type[orm_models.BlockSchema]

A block schema model

BlockSchemaReference ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L285" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

BlockSchemaReference(self) -> type[orm_models.BlockSchemaReference]

A block schema reference model

BlockType ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L275" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

BlockType(self) -> type[orm_models.BlockType]

A block type model

CompositeTriggerChildFiring ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L330" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

CompositeTriggerChildFiring(self) -> type[orm_models.CompositeTriggerChildFiring]

A model capturing a composite trigger's child firing

ConcurrencyLimit ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L250" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

ConcurrencyLimit(self) -> type[orm_models.ConcurrencyLimit]

A concurrency model

ConcurrencyLimitV2 ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L255" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

ConcurrencyLimitV2(self) -> type[orm_models.ConcurrencyLimitV2]

A v2 concurrency model

Configuration ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L300" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Configuration(self) -> type[orm_models.Configuration]

An configuration model

CsrfToken ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L260" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

CsrfToken(self) -> type[orm_models.CsrfToken]

A csrf token model

Deployment ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L220" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Deployment(self) -> type[orm_models.Deployment]

A deployment orm model

DeploymentSchedule ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L225" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

DeploymentSchedule(self) -> type[orm_models.DeploymentSchedule]

A deployment schedule orm model

Event ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L342" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Event(self) -> type[orm_models.Event]

An event model

EventResource ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L347" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

EventResource(self) -> type[orm_models.EventResource]

An event resource model

Flow ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L180" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Flow(self) -> type[orm_models.Flow]

A flow orm model

FlowRun ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L185" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

FlowRun(self) -> type[orm_models.FlowRun]

A flow run orm model

FlowRunInput ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L310" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

FlowRunInput(self) -> type[orm_models.FlowRunInput]

A flow run input model

FlowRunState ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L190" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

FlowRunState(self) -> type[orm_models.FlowRunState]

A flow run state orm model

Log ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L245" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Log(self) -> type[orm_models.Log]

A log orm model

SavedSearch ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L230" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

SavedSearch(self) -> type[orm_models.SavedSearch]

A saved search orm model

TaskRun ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L195" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

TaskRun(self) -> type[orm_models.TaskRun]

A task run orm model

TaskRunState ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L200" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

TaskRunState(self) -> type[orm_models.TaskRunState]

A task run state orm model

TaskRunStateCache ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L215" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

TaskRunStateCache(self) -> type[orm_models.TaskRunStateCache]

A task run state cache orm model

Variable ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L305" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Variable(self) -> type[orm_models.Variable]

A variable model

WorkPool ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L235" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

WorkPool(self) -> type[orm_models.WorkPool]

A work pool orm model

WorkQueue ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L265" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

WorkQueue(self) -> type[orm_models.WorkQueue]

A work queue model

Worker ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L240" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Worker(self) -> type[orm_models.Worker]

A worker process orm model

create_db ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L75" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

create_db(self) -> None

Create the database

dialect ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L171" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

dialect(self) -> type[sa.engine.Dialect]

drop_db ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L79" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

drop_db(self) -> None

Drop the database by removing all tables directly.

This reflects the actual database schema and drops every table rather than running all Alembic downgrade migrations in reverse. Running downgrades is fragile because individual migration downgrade steps may fail on real-world data (e.g. re-adding a foreign key constraint when orphaned references exist). Dropping tables directly is both faster and more robust.

Reflection is used instead of Base.metadata.drop_all() so that tables created by migrations but not tracked in the ORM (e.g. deployment_version, alembic_version) are also removed.

engine ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L133" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

engine(self) -> AsyncEngine

Provides a SqlAlchemy engine against a specific database.

is_db_connectable ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L121" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

is_db_connectable(self) -> bool

Returns boolean indicating if the database is connectable. This method is used to determine if the server is ready to accept requests.

run_migrations_downgrade ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L117" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

run_migrations_downgrade(self, revision: str = '-1') -> None

Run all downgrade migrations

run_migrations_upgrade ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L113" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

run_migrations_upgrade(self) -> None

Run all upgrade migrations

session ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L141" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

session(self) -> AsyncSession

Provides a SQLAlchemy session.

session_context ^{<a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/database/interface.py#L149" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

session_context(self, begin_transaction: bool = False, with_for_update: bool = False)

Provides a SQLAlchemy session and a context manager for opening/closing the underlying connection.

Args:

• begin_transaction: if True, the context manager will begin a SQL transaction. Exiting the context manager will COMMIT or ROLLBACK any changes.