多个MYSQL查询与多个PHP foreach循环 [英] Multiple MYSQL queries vs. Multiple php foreach loops

问题描述

数据库结构：

  id galleryId类型文件名描述
 1`artists_2010-01-15_7c1ec``图片` `band602.jpg``红伞促销'
 2`artists_2010-01-15_7c1ec``图片``nov7.jpg``CD发行方`
 3`artists_2010-01-15_7c1ec`` video` `band.flv``Presskit` 
  

我要将图片拉出应用程序，在另一个视频等，是更好的做每个部分多个MySQL查询如此：

  $ query = mysql_query （SELECT * FROM galleries WHERE galleryId ='$ galleryId'&& type ='image'）; 
  

感谢您的帮助，感谢您的支持。想法。

解决方案

这取决于更重要的是：可读性还是性能，我期望一个查询和预填充PHP数组将会更快执行，因为数据库连接是昂贵的，但是每个部分的一个简单的查询更具可读性。

除非你知道（而不只是希望），否则你会得到大量的流量，我会去单独的查询，然后担心优化，如果它看起来像一个问题。到那时，还会有其他的事情要做，比如构建数据访问层并添加一些缓存。

Database structure:

id  galleryId                 type     file_name       description
1   `artists_2010-01-15_7c1ec`  `image`  `band602.jpg`   `Red Umbrella Promo`
2   `artists_2010-01-15_7c1ec`  `image`  `nov7.jpg`      `CD Release Party`
3   `artists_2010-01-15_7c1ec`  `video`  `band.flv`      `Presskit`

I'm going to pull images out for one section of an application, videos on another, etc. Is it better to make multiple mysql queries for each section like so:

$query = mysql_query("SELECT * FROM galleries WHERE galleryId='$galleryId' && type='image');

...Or should I be building an associative array and just looping through the array over and over whenever I need to use the result set?

Thanks for the thoughts.

解决方案

It depends what's more important: readability or performance. I'd expect a single query and prefilling PHP arrays would be faster to execute, since database connections are expensive, but then a simple query for each section is much more readable.

Unless you know (and not just hope) you're going to get a huge amount of traffic I'd go for separate queries and then worry about optimising if it looks like it'll be a problem. At that point there'll be other things you'll want to do anyway, such as building a data access layer and adding some caching.

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