显示标记

Question

考虑这个SQL查询：

SELECT * FROM 
( 
SELECT * FROM wp_postmeta 
WHERE 
(
meta_key = 'latitude' AND meta_value *1 BETWEEN 47.3641471102 AND 47.3731524898) 
OR (meta_key = 'longitude' AND meta_value *1 BETWEEN 8.53253429117 AND 8.54583070883) 
) 
AS PostMeta, wp_posts 
WHERE wp_posts.id = PostMeta.post_id order by post_id asc 

它给了我符合特定值或特定值之间的经度之间要么纬度的所有记录。我想得到的是符合两个值的记录。 但将查询中的'OR'更改为'AND'将给我零结果。

我想我需要做某种子查询，但不知道如何做到这一点。

有人吗？

Answer 1

你真的只需要从你的经度子查询中分离你的纬度子查询。现在，我有更多的时间，我会更明确地返工查询：

SELECT 
    /* You're only interested in the wp_posts data, right? */ 
    /* You don't care about the data from wp_postmeta. */ 
    /* Only select the data you're actually going to use. */ 
    /* Ideally you'd specify each column in wp_posts that you're */ 
    /* going to use and ignore the rest */ 
    p.* 
FROM 
    wp_posts p 
     JOIN (SELECT post_id FROM wp_postmeta WHERE meta_key = 'latitude' AND CAST(meta_value AS DECIMAL) BETWEEN 47.3641471102 AND 47.3731524898) lat ON p.id = lat.post_id 
     JOIN (SELECT post_id FROM wp_postmeta WHERE meta_key = 'longitude' AND CAST(meta_value AS DECIMAL) BETWEEN 8.53253429117 AND 8.54583070883) long ON p.id = long.post_id 
ORDER BY 
    post_id ASC 

......因为没有哪一个wp_postmeta记录将既是纬度和经度，你不能（至少不近就像这样）在相同的WHERE子句中匹配它们。相反，创建两个单独的调用wp_postmeta表，一个纬度和一个经度，并迫使他们都匹配（因此INNER JOIN，而不是LEFT JOIN）