PHP开发简单图书借阅系统完整还书功能实现代码
引入数据库文件config.php
<?php include("config.php");?>
创建完整的还书代码文件huanshu.php
<?php require ('config.php'); //如果没有登录,退出 if ($_SESSION['id']==""){ echo "<script language=javascript>alert('您还没有登陆');window.location='landing.php'</script>"; exit(); } $book_id=$_GET["book_id"]; //构建sql语句还书 //在lend表中删除该借书记录 $returnsql="DELETE FROM lend where book_id='$book_id' and user_id=".$_SESSION['id']; mysqli_query($link,$returnsql) or die ("删除借书记录失败:".mysqli_errno($link)); //在book表中增加一本现存书数量 $booksql="UPDATE yx_books SET leave_number=leave_number+1 where id='$book_id'"; mysqli_query($link,$booksql) or die ("增加剩余书数量失败:".mysqli_error($link)); echo "<script language=javascript>alert('还书成功');window.location='index.php'</script>"; ?>