:: a typeCtrl KGHC 9.14.1 · lts/ghc-9.14.x · 45dd537 · 2026-10-11
Moduleyesod-persistent-1.6.0.9Haskell2010
Defines the core functionality of this package. This package is distinguished from Yesod.Persist in that the latter additionally exports the persistent modules themselves.
type family YesodPersistBackend siterunDB :: YesodDB site a -> HandlerFor site aAllows you to execute database actions within Yesod Handlers. For databases that support it, code inside the action will run as an atomic transaction.
userId <- runDB $ do
userId <- insert $ User "username" "email@example.com"
insert_ $ UserPreferences userId True
pure userIdHelper for creating runDB.
Since 1.2.0
Since 1.2.0
getDBRunner :: HandlerFor site (DBRunner site, HandlerFor site ())This function differs from runDB in that it returns a database runner function, as opposed to simply running a single action. This will usually mean that a connection is taken from a pool and then reused for each invocation. This can be useful for creating streaming responses; see runDBSource.
It additionally returns a cleanup function to free the connection. If your code finishes successfully, you must call this cleanup to indicate changes should be committed. Otherwise, for SQL backends at least, a rollback will be used instead.
Since 1.2.0
Helper for implementing getDBRunner.
Since 1.2.0
DBRunnerrunDBRunner :: forall a. YesodDB site a -> HandlerFor site aLike runDB, but transforms a Source. See respondSourceDB for an
example, practical use case.
Since 1.2.0
Extends respondSource to create a streaming database response body.
Get the given entity by ID, or return a 404 not found if it doesn't exist.
Get the given entity by unique key, or return a 404 not found if it doesn't exist.
Create a new record in the database, returning an automatically created key, or raise a 400 bad request if a uniqueness constraint is violated.
Same as insert400, but doesn’t return a key.