仅将唯一表项从一个表复制到另一个MySQL

Question

I'm trying to create scheduled auto-updater for MySQL DB. The script I use is shown below. It's idea is to insert only unique products from table wp_posts to table export_copy. But this one inserts nothing. Please help me to fix the script.

 INSERT INTO `export_copy`(`name`, `link`) SELECT p.post_title, p.guid FROM wp_posts p WHERE NOT EXISTS ( SELECT * FROM export_copy, wp_posts WHERE export_copy.id=wp_posts.ID) 

Answer 1

Your query will never work!

Since your table's name is "wp_posts" ,it seem you want copy data from wordpress table to your own

you can handle this by php, firt you must fetch data from table and save that to an array, then export array to insert query

$link = mysqli_connect(Your_HOST , Your_User , YOUR_Pass, DB_NAME);
$q = "SELECT p.post_title, p.guid FROM wp_posts p WHERE NOT EXISTS ( SELECT * FROM export_copy, wp_posts WHERE export_copy.id=wp_posts.ID)";
$result = mysqli_query($link, $q);
$i=0;
while($row=mysqli_fetch_assoc($result))
{
    $a[$i]['name'] = $row['post_title'];
    $a[$i]['link'] = $row['post_title'];
    $i++;
}
$q = '';
foreach($a as $a)
    $q .= "('".$a['name']."','".$a['link']."'),";

$q = substr($q,0, (strlen($q)-1));
$q = "INSERT INTO `export_copy`(`name`, `link`) VALUES " . $q;
$result = mysqli_query($link, $q);