PHP：使用getimagesize在数据库中输入图像尺寸

Question

I have a number of images who's information is stored in a MySQL database. The images themselves are stored in a folder, but the database contains their URL as well as other pertinent data.

I came across the PHP getimagesize which I was thinking of using to populate the width= and height= properties of the img tags of each image. However, I have been told that the overhead for this (as there are hundreds of images) will slow down the page load substantially.

I'm curious if there is a way to use getimagesize to search out all the images from their information in the database, calculate their width and height, and then insert the data into their respective width and height fields in the database, Thus allowing a simple sql query to do the work?

Here is my database structure:

CREATE TABLE `secondary_images` (
  `imgId` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `primaryId` int(10) unsigned DEFAULT NULL,
  `imgURL` varchar(255) DEFAULT NULL,
  `width` varchar(255) DEFAULT NULL,
  `height` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`imgId`),
  KEY `primaryId` (`primaryId`),
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 ;

Answer 1

$image_folder = "images/";
$res = mysql_query('SELECT * FROM secondary_images')
while ($row = mysql_fetch_assoc($res)) {
    $size = getimagesize($image_folder.$row['imgUrl']);
    mysql_query("UPDATE secondary_images SET width='{$size[0]}', height='{$size[1]} WHERE imgId='{$row['imgId']}'");
}

Why do you want to put image size in html anyway?