您尝试分配一个具有相同名称的值.因此，最后一个值将替换为现有值.

You try to assign a value with same name.so your last value replace with the existing value.

例如:您的URL看起来像

for example :your URL look like,

http://www.example.com/index.php?finished_product_name=abc&material_name=xxx&finished_product_name=pqr&material_name=yyy

所以您的$_GET['finished_product_name']的值是pqr而不是abc.

so your $_GET['finished_product_name'] has value is pqr not abc.

如果您可以使用include []更改字段名称，则PHP将创建一个包含所有匹配值的数组:

If you can change the field name with include [], then PHP will create an array containing all of the matching values:

http://www.example.com/index.php?id[]=123&version[]=3&id[]=234&version[]=4

您的网址示例，

http://www.example.com/index.php?finished_product_name[]=abc&material_name[]=xxx&finished_product_name[]=pqr&material_name[]=yyy

您的for循环是:

for ($i=0; $i < count($_POST['finished_product_name']); $i++ )
{
    $product =$_POST['finished_product_name'][$i];
    $material = $_POST['material_name'][$i];
    $quantity = $_POST'product_quantity'][$i]; 
}