使用内部联接超过3个表的SQL删除

Question

I run this sql statement to delete from database using inner join, but i get too many errors

Error

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'INNER JOIN ipaddress_likes_map ON ipaddress_likes_map.postat = blog_post.BID INN' at line 3' in C:\\xampp\\htdocs\\codejail.net_inc\\dbcontroller.php:57 Stack trace: #0 C:\\xampp\\htdocs\\codejail.net_inc\\dbcontroller.php(57): PDOStatement->execute() #1 C:\\xampp\\htdocs\\codejail.net\\user\\deleteaccount.php(88): DBController->execute() #2 {main} thrown in C:\\xampp\\htdocs\\codejail.net_inc\\dbcontroller.php on line 57

here is my code

<?php
   if(isset($_POST['delete'])){
     $pass = $_POST['pasyske'];
     $userkey = $_POST['username'];
     $db_delete = new DBController();
     $db_delete->prepare("DELETE
FROM blog_post
INNER JOIN ipaddress_likes_map ON ipaddress_likes_map.postat = blog_post.BID
INNER JOIN flagpost ON flagpost.postId = blog_post.BID
INNER JOIN postviewmap ON postviewmap.viewpostId = blog_post.BID
INNER JOIN replys ON replys.rid = blog_post.BID
INNER JOIN votepoint_map ON votepoint_map.postlike_id = blog_post.BID
WHERE blog_post.UserName = :alluserpost");
     $db_delete->bind(":alluserpost", $userkey);
     //$db_delete->bind(":password", $encrypt_password);
     $db_delete->execute();
     $pdeleted = $db_delete->getAll(); 
     $db_delete->free();

    if($pdeleted){
        print_r($pdeleted);
    }

   }?>

I'm sure my db controller is okay because when i run single delete statement it work very fine

Answer 1

After DELETE you should tell from what table to delete rows. Try this query:

$db_delete->prepare("DELETE blog_post 
FROM blog_post
INNER JOIN ipaddress_likes_map ON ipaddress_likes_map.postat = blog_post.BID
INNER JOIN flagpost ON flagpost.postId = blog_post.BID
INNER JOIN postviewmap ON postviewmap.viewpostId = blog_post.BID
INNER JOIN replys ON replys.rid = blog_post.BID
INNER JOIN votepoint_map ON votepoint_map.postlike_id = blog_post.BID
WHERE blog_post.UserName = :alluserpost");

Answer 2

Give each table an alias and reference it right after the word DELETE . Also, use LEFT JOIN instead of INNER JOIN because I'm guessing you still want the deletes to work event if some of the joined tables don't have matching rows.

db_delete->prepare("DELETE bp, i, f, p, r, v
FROM blog_post AS bp
LEFT JOIN ipaddress_likes_map AS i ON i.postat = bp.BID
LEFT JOIN flagpost AS f ON f.postId = bp.BID
LEFT JOIN postviewmap AS p ON p.viewpostId = bp.BID
LEFT JOIN replys AS r ON r.rid = bp.BID
LEFT JOIN votepoint_map AS v ON v.postlike_id = bp.BID
WHERE bp.UserName = :alluserpost");