使用外键在另一个表中插入图像

Question

I have two tables in my db, telephones(id, title, price) and images(id, tp_id, photos) I went in the images table and put a foreign key on the tp_id column to match the id in the telephones table so that every image is linked to a telephone . But the problem is my images go into the table fine but the tp_id column always has the value of 0, what I am missing here? can somebody guide me? Thanks

PS: I know about the security vulnerability of my code I am just doing some test here!

<?php

if (isset($_POST['submit'])) {

    include 'dbconnect.php';


    for ($i = 0; $i < count($_FILES["photo"]["name"]); $i++) {


        $target = "img/"; //This is the directory where images will be saved 
        $target_files = $target . basename($_FILES['photo']['name'][$i]); //This gets all the other information from the form
        $ad_title = $_POST['title'];
        $ad_price = $_POST['price'];
        $ad_photo = $target . ($_FILES['photo']['name'][$i]);

        if (!move_uploaded_file($_FILES['photo']['tmp_name'][$i], $target_files)) { //Tells you if its all ok 
            echo "Sorry, there was a problem uploading your file.";
        } else { //Gives and error if its not 
            $sql = "INSERT INTO telephones (title, price) VALUES ('$ad_title', '$ad_price')";
            $conn->query($sql);

            $sql1 = "INSERT INTO images (photos) VALUES ('$ad_photo') ";
            $conn->query($sql1);
//Writes the photo to the server

            header('location: addconfirm.php');
        }
    }
}
?>

Answer 1

使用此获取最后插入的主键值

$last_id = $conn->insert_id;

Answer 2

You need to get last insert id form telephones table using $conn->insert_id; and the insert into images table as

 $sql = "INSERT INTO telephones (title, price) VALUES ('$ad_title', '$ad_price')";                      
            $conn->query($sql);
            $tp_id=$conn->insert_id;// get last insert id

 $sql1 = "INSERT INTO images (photos,tp_id) VALUES ('$ad_photo',$tp_id) ";
            $conn->query($sql1);

Note:- Your script is Open for sql injection check How can I prevent SQL injection in PHP? to prevent it

Answer 3

Question has already been answered many times Use : MySQL: LAST_INSERT_ID()

 $sql = "INSERT INTO telephones (title, price) VALUES ('$ad_title', '$ad_price')";                      
 $conn->query($sql);
 $tp_last_insert_id = $conn->LAST_INSERT_ID;// get last insert id

you should call this function right after you insert to get the latest added id

 $sql1 = "INSERT INTO images (photos,tp_id) VALUES ('$ad_photo',$tp_last_insert_id) ";
  $conn->query($sql1);