从多个列组合中选择表中的数据

Question

我试图从基于height和width列的多个组合的表中选择数据。但是，我正在使用的查询不起作用。

$sql_wallpaper = " 
    SELECT * 
    FROM wallpaper 
    WHERE categoryid = $catid 
    WHERE height = 1080 
    OR width = 2560 
    OR width = 1366 
    OR height = 720 
    OR width = 2560 
    AND height = 1600 
    OR width = 1680 
    AND height = 1050 
    OR width = 1920 
    AND height = 1200 
    OR width = 1280 
    AND height = 800 
    OR width = 1440 
    AND height = 900 
    ORDER BY wallpaperid DESC 
    LIMIT $from,$max_results 
"; 

我该如何解决这个问题？

Answer 1

这是因为你的SQL是错误的：

select * from wallpaper 
    where categoryid = $catid 
    where height = 1080 OR width = 2560 OR width = 1366 
    OR height = 720 OR width = 2560 AND height = 1600 
    OR width = 1680 AND height = 1050 OR width = 1920 
    AND height = 1200 OR width = 1280 AND height = 800 
    OR width = 1440 AND height = 900 
    order by wallpaperid desc 
    limit $from,$max_results 

你在那里有两个WHERE秒。您应该使用AND代替第二个，也许将所有内容都包装成parens。

但也可以尝试在脚本中使用print mysql_error()。尤其对于某些不起作用的调试。 MySQL会在大多数时候告诉你你的查询有什么问题。

---

很好。您的重写查询：

select * from wallpaper 
    where categoryid = $catid 
    AND (
     height = 1080 OR width = 2560 OR width = 1366 
    OR height = 720 OR width = 2560 AND height = 1600 
    OR width = 1680 AND height = 1050 OR width = 1920 
    AND height = 1200 OR width = 1280 AND height = 800 
    OR width = 1440 AND height = 900 
     ) 
    order by wallpaperid desc 
    limit $from,$max_results 

但你可能需要使用简单的是：

SELECT * FROM wallpaper 
    WHERE categoryid = $catid 
    AND width IN (1440, 2560, 1366, 1680, 1920, 1280) 
    AND height IN (1200, 800, 900, 1080, 720, 1600, 1050) 
    ORDER BY wallpaperid DESC 
    LIMIT $from,$max_results