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我是一名学习Haskell的Java程序员.
我在一个小型网络应用程序上工作,该应用程序使用Happstack并通过HDBC与数据库进行通信.

我编写了select和exec函数,我就像这样使用它们:

module Main where

import Control.Exception (throw)

import Database.HDBC
import Database.HDBC.Sqlite3 -- just for this example, I use MySQL in production

main = do
    exec "CREATE TABLE IF NOT EXISTS users (name VARCHAR(80) NOT NULL)" []

    exec "INSERT INTO users VALUES ('John')" []
    exec "INSERT INTO users VALUES ('Rick')" []

    rows <- select "SELECT name FROM users" []

    let toS x = (fromSql x)::String
    let names = map (toS . head) rows

    print names …