module Main.Transactions where import Prelude import Hasql.Transaction import qualified Main.Statements as A createSchema :: Transaction () createSchema = do statement () A.createAccountTable dropSchema :: Transaction () dropSchema = do statement () A.dropAccountTable transfer :: Int64 -> Int64 -> Scientific -> Transaction Bool transfer id1 id2 amount = do success <- statement (id1, amount) A.modifyBalance if success then statement (id2, negate amount) A.modifyBalance else return False transferTimes :: Int -> Int64 -> Int64 -> Scientific -> Transaction () transferTimes times id1 id2 amount = replicateM_ times (transfer id1 id2 amount)