php - 多重插入语句

Question

我想记录用户输入的值，同时从另一个表中复制单个数据。可能吗？

这是我的代码:

$sql="INSERT INTO grades (studentnumber,subjectcode)
VALUES
('$_POST[studentnumber]','$_POST[subjectcode]')";

$sql="INSERT INTO grades (course) SELECT course FROM students WHERE studentnumber= '$_POST[studentnumber]'";

if (!mysql_query($sql,$con))
  {
  die('Error: ' . mysql_error());
  }
echo "<script type='text/javascript'>alert('Record Successfully Added'); location.href = '../instructor/cvsu-sis_students.php';</script>";

在此先感谢您提出我的基本问题。

Answer 1

如果这就是您要问的问题，您可以在一个查询中完成，还记得转义字符串以避免 SQL 注入(inject):

$P_studentnumber=mysql_real_escape_string($_POST['studentnumber']);
$P_subjectcode=mysql_real_escape_string($_POST['subjectcode']);

$sql="INSERT INTO grades (studentnumber,subjectcode,course) SELECT '$P_studentnumber','$P_subjectcode',course FROM students WHERE studentnumber='$P_studentnumber'";

if (!mysql_query($sql,$con))
{
   die('Error: ' . mysql_error());
}
echo "<script type='text/javascript'>alert('Record Successfully Added'); location.href = '../instructor/cvsu-sis_students.php';</script>";