slick.dbio

The base trait for the context object passed to synchronous database actions by the execution engine.

A DBIOAction that represents a seq or andThen operation for sequencing in the DBIOAction monad. Unlike SequenceAction it only keeps the last result.

A DBIOAction that represents an asTry operation.

A DBIOAction that represents a cleanUp operation for sequencing in the DBIOAction monad.

A Database I/O Action that can be executed on a database. The DBIOAction type allows a separation of execution logic and resource usage management logic from composition logic. DBIOActions can be composed with methods such as andThen, andFinally and flatMap. Individual parts of a composite DBIOAction are always executed serially on a single database, but possibly in different database sessions, unless the session is pinned either explicitly (using withPinnedSession) or implicitly (e.g. through a transaction).

The actual implementation base type for all Actions is DBIOAction. StreamingDBIO and DBIO are type aliases which discard the effect type (and the streaming result type in the latter case) to make DBIOAction types easier to write when these features are not needed. All primitive DBIOActions and all DBIOActions produced by the standard combinators in Slick have correct Effect types and are streaming (if possible).

A DBIOAction that represents a database operation. Concrete implementations are backend-specific.

A phantom type for annotating DBIOActions with specific effects (e.g. Write or Transactional). Effects can be composed through intersection types (e.g. Write with Transactional. The standard Slick back-ends do not restrict the evaluation of actions based on effects but they can be used in user-level code (e.g. for ensuring that all writes go to a master database but reads can also be performed by a slave).

A DBIOAction that represents a failed operation.

A DBIOAction that fails.

A DBIOAction that represents a flatMap operation for sequencing in the DBIOAction monad.

An asynchronous DBIOAction that returns the result of a Future.

A DBIOAction that attaches a name for logging purposes to another action.

A phantom type used as the streaming result type for DBIOActions that do not support streaming. Note that this is a supertype of Streaming (and it is used in covariant position), so that any streaming action can be used where a non-streaming action is expected.

A DBIOAction that represents a sequence or operation for sequencing in the DBIOAction monad.

A phantom type used as the streaming result type for DBIOActions that do support streaming.

An ActionContext with extra functionality required for streaming DBIOActions.

A DBIOAction that returns a constant value.

A synchronous database action provides a function from an ActionContext to the result type. BasicBackend.DatabaseDef.run supports this kind of action out of the box through BasicBackend.DatabaseDef.runSynchronousDatabaseAction so that run does not need to be extended if all primitive database actions can be expressed in this way. These actions also implement construction-time fusion for the andFinally, andThen, asTry, failed, withPinnedSession and zip operations.

The execution engine ensures that an ActionContext is never used concurrently and that all state changes performed by one invocation of a SynchronousDatabaseAction are visible to the next invocation of the same or a different SynchronousDatabaseAction.

Simplified type for a DBIOAction without streaming or effect tracking

Simplified type for a streaming DBIOAction without effect tracking