Mysql查询检查数据库中是否存在url

Question

lets say I have $_POST['url']=' http://myexamplesite.com/images/image.jpg '; how can I get correct result if this url exists in the database but looks like: http://www.myexamplesite.com/images/image.jpg

if I do:

$q='select id from products where url LIKE "%'.$_POST['url'].'%"';

This will not return always correct results. What is the correct way? Thanks

Answer 1

If you need pure SQL solution, you can use SUBSTRING_INDEX() for that:

SELECT * FROM products WHERE
SUBSTRING_INDEX(SUBSTRING_INDEX(url, 'http://', -1), 'www.',-1) = 
SUBSTRING_INDEX(SUBSTRING_INDEX('".$_POST['url']."', 'http://', -1), 'www.',-1)

This will remove http:// and www. from both strings and will compare the rest.

Answer 2

Either

1) Standardise the URLs within the database if they are all on your own site

or

2) Remove the http://, http://, and www. from search URL like so:

function pure_url($url) {
   if ( substr($url, 0, 7) == 'http://' ) {
      $url = substr($url, 7);
   }
   if ( substr($url, 0, 8) == 'https://' ) {
      $url = substr($url, 8);
   }
   if ( substr($url, 0, 6) == 'ftp://') {
      $url = substr($url, 6);
   }
   if ( substr($url, 0, 4) == 'www.') {
      $url = substr($url, 4);
   }
   return $url;
}

$url = pure_url('http://www.myexamplesite.com/images/image.jpg');
// $url = 'myexamplesite.com/images/image.jpg';