Analogous to runDB for cabal repl.

runDBDev.hs

import Prelude
import Control.Monad.Logger (LoggingT, runStdoutLoggingT)
import Control.Monad.Trans.Resource (ResourceT, runResourceT)
import qualified Database.Persist
import Database.Persist.Sql (SqlPersistT, runSqlPool)
import qualified Settings
import Yesod.Default.Config (DefaultEnv(Development), withYamlEnvironment)

runDBDev :: SqlPersistT (LoggingT (ResourceT IO)) a -> IO a
runDBDev m = do
    dbconf <- withYamlEnvironment "config/postgresql.yml" Development
                  Database.Persist.loadConfig >>= Database.Persist.applyEnv
    pool <- Database.Persist.createPoolConfig (dbconf :: Settings.PersistConf)
    runResourceT $ runStdoutLoggingT $ runSqlPool m pool