Delete from two or more tables

Question

lets says i have these variable:

$post_id = 222;

$IsLoggIn =2;

I have same column "post_id" name in five different tables. I want to write an sql statement to check and see if there is a row with column name "post_id" whose value is equal to variable "$post_id" and delete that row

Note: Apart from the "public_feed_table" , it is possible there could be no row with post_id equal to variable "$post_id" so the sql statement should check if there is a row before deleting.

I want a single sql statement that can do this job.

What I tried is below. Please help:

global      $dbc_conn,
            $public_feed_table,
            $images_table,
            $comments_table,
            $rating_table,
            $notification_table,    
            $IsLoggIn;

$sql    =   "DELETE 
                        p,i,c,r,n
                            FROM
                                $public_feed_table p
                                    LEFT JOIN 
                                    $images_table i,
                                    $comments_table c,
                                    $rating_table r,
                                    $notification_table n
                                        ON
                                        i.post_id,
                                        c.post_id,
                                        r.post_id,
                                        n.post_id=p.post_id

                                        WHERE p.post_id='$post_id'
                                        AND p.user_id='$IsLoggIn'

                                        ";
            //query database
            $query  =   mysqli_query($dbc_conn,$sql);

Answer 1

You join Syntax is worng. It must be:

       $sql    =   "DELETE p,i,c,r,n
                        FROM
                        $public_feed_table p
                            LEFT JOIN 
                            $images_table i ON
                             p.post_id = i.post_id

                            LEFT JOIN
                            $comments_table c ON 
                            p.post_id = c.post_id

                            LEFT JOIN
                            $rating_table r ON  
                            p.post_id = r.post_id 

                            LEFT JOIN
                            $notification_table n ON
                            p.post_id=n.post_id

                                WHERE p.post_id='$post_id'
                                AND p.user_id='$IsLoggIn'

                                ";

For more Information see: http://www.w3schools.com/sql/sql_join_left.asp

Answer 2

Your JOIN syntax is total weird. It rather should be

                        FROM
                            $public_feed_table p
                                LEFT JOIN 
                                $images_table i ON i.col = p.col,
                                LEFT JOIN $comments_table c ON p.col = c.col,

** col is for example, substitute it with actual column name per your table schema