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mmhelloworld/JdbcExample.idr

Created January 16, 2017 07:18
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An Idris example using a database with JDBC and idris-jvm
Raw
JdbcExample.idr
module Main
import IdrisJvm.IO
namespace ResultSet
ResultSet : Type
ResultSet = JVM_Native $ Interface "java/sql/ResultSet"
next : ResultSet -> JVM_IO Bool
next = invokeInstance "next" (ResultSet -> JVM_IO Bool)
getInt : ResultSet -> String -> JVM_IO Int
getInt = invokeInstance "getInt" (ResultSet -> String -> JVM_IO Int)
getString : ResultSet -> String -> JVM_IO String
getString = invokeInstance "getString" (ResultSet -> String -> JVM_IO String)
namespace PreparedStatement
PreparedStatement : Type
PreparedStatement = JVM_Native $ Interface "java/sql/PreparedStatement"
setInt : PreparedStatement -> Int -> Int -> JVM_IO ()
setInt = invokeInstance "setInt" (PreparedStatement -> Int -> Int -> JVM_IO ())
setString : PreparedStatement -> Int -> String -> JVM_IO ()
setString = invokeInstance "setString" (PreparedStatement -> Int -> String -> JVM_IO ())
executeUpdate : PreparedStatement -> JVM_IO Int
executeUpdate = invokeInstance "executeUpdate" (PreparedStatement -> JVM_IO Int)
executeQuery : PreparedStatement -> JVM_IO ResultSet
executeQuery = invokeInstance "executeQuery" (PreparedStatement -> JVM_IO ResultSet)
close : PreparedStatement -> JVM_IO ()
close = invokeInstance "close" (PreparedStatement -> JVM_IO ())
namespace Connection
Connection : Type
Connection = JVM_Native $ Interface "java/sql/Connection"
prepareStatement : Connection -> String -> JVM_IO PreparedStatement
prepareStatement = invokeInstance "prepareStatement" (Connection -> String -> JVM_IO PreparedStatement)
commit : Connection -> JVM_IO ()
commit = invokeInstance "commit" (Connection -> JVM_IO ())
close : Connection -> JVM_IO ()
close = invokeInstance "close" (Connection -> JVM_IO ())
namespace DriverManager
DriverManagerClass : JVM_NativeTy
DriverManagerClass = Class "java/sql/DriverManager"
getConnection : String -> JVM_IO Connection
getConnection = invokeStatic DriverManagerClass "getConnection" (String -> JVM_IO Connection)
createQuery : String
createQuery = "CREATE TABLE TODO(id int primary key, description varchar(255))"
insertQuery : String
insertQuery = "INSERT INTO TODO (id, description) values (?,?)"
selectQuery : String
selectQuery = "select * from TODO"
addTodo : Connection -> Int -> String -> JVM_IO ()
addTodo connection id todo = do
insertStmt <- prepareStatement connection insertQuery
setInt insertStmt 1 id
setString insertStmt 2 todo
executeUpdate insertStmt
PreparedStatement.close insertStmt
printRow : ResultSet -> JVM_IO ()
printRow rs = do
id <- getInt rs "id"
desc <- getString rs "description"
printLn $ "Id: " ++ show id ++ ", TODO: " ++ desc
main : JVM_IO ()
main = do
connection <- DriverManager.getConnection "jdbc:derby:memory:testDB;create=true"
createStmt <- prepareStatement connection createQuery
executeUpdate createStmt
PreparedStatement.close createStmt
addTodo connection 1 "Learn Haskell"
addTodo connection 2 "Learn Idris"
selectStmt <- prepareStatement connection selectQuery
rs <- executeQuery selectStmt
while (next rs) $ printRow rs
PreparedStatement.close selectStmt
Connection.close connection
Raw
run.txt
$ idrisjvm JdbcExample.idr -o target
$ java -cp target:/path/to/idris-jvm-runtime-1.0-SNAPSHOT.jar:/path/to/derby.jar main.Main
"Id: 1, TODO: Learn Haskell"
"Id: 2, TODO: Learn Idris"
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