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import Database.HaskellDB
import Dp037.Test_tb1
import TestConnect
printTable db =
do
t <- query db (table test_tb1)
mapM_ (putStrLn . showRow) t
showRow r = lpad 10 (show (r!c11)) ++ lpad 10 (showNullable (r!c12))
showNullable :: Show a => Maybe a -> String
showNullable = maybe "NULL" show
lpad :: Int -> String -> String
lpad x s = replicate (x - length s) ' ' ++ s
testInsert db =
do
insert db test_tb1 (c11 << constant 157 # c12 << constant (Just 56))
insert db test_tb1 (c11 << constant (-567) # c12 << constant Nothing)
testUpdate db =
do
update db test_tb1 (\r -> r!c11 .==. constant 157) (setC12 (Just 18))
where
setC12 x r = c12 << constant x
testDelete db =
do
delete db test_tb1 (\r -> r!c11 .==. constant 157 .||. isNull (r!c12))
test db =
do
putStrLn "Before insert:"
printTable db
testInsert db
putStrLn "After insert:"
printTable db
testUpdate db
putStrLn "After update:"
printTable db
testDelete db
putStrLn "After delete:"
printTable db
main = argConnect test
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