Unknown column 'latitude' in 'field list' - mysql

Question

SELECT GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ",")
, SUBSTRING_INDEX(GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ","),",",1) latitude
, SUBSTRING_INDEX(SUBSTRING_INDEX(GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ","),",",2),",",-1) longitude
, ( 6371 * acos( cos( radians(52.2734487789) ) * cos( radians(latitude ) ) * cos( radians(longitude ) - radians(10.5438383386) ) + sin( radians(52.2734487789) ) * sin( radians(latitude ) ) ) ) AS distance
FROM `wp_umkreissuche_posts` AS posts
, `wp_umkreissuche_postmeta` AS postmeta
WHERE posts.post_type = "adresses"
AND posts.ID=postmeta.post_id
AND postmeta.meta_key="latitude"
OR posts.post_type="adresses"
AND posts.ID=postmeta.post_id
AND postmeta.meta_key="longitude"
GROUP
BY postmeta.post_id
HAVING distance < 0.5
ORDER
BY postmeta.post_id
, distance ASC

Answer 1

This is your query, formatted a bit better and with clearer join syntax:
SELECT GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ","),
SUBSTRING_INDEX(GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ","),",",1) AS latitude,
SUBSTRING_INDEX(SUBSTRING_INDEX(GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ","),",",2),",",-1) AS longitude,
( 6371 * acos( cos( radians(52.2734487789) ) * cos( radians(latitude ) ) * cos( radians(longitude ) - radians(10.5438383386) ) + sin( radians(52.2734487789) ) * sin( radians(latitude ) ) ) ) AS distance
FROM `wp_umkreissuche_posts` AS posts JOIN
`wp_umkreissuche_postmeta` AS postmeta
ON posts.ID = postmeta.post_id AND posts.post_type = 'adresses' AND
(postmeta.meta_key IN ('latitude', 'longitude')
)
GROUP BY postmeta.post_id
HAVING distance < 0.5
ORDER BY postmeta.post_id, distance ASC
Your direct problem is that latitude and longitude are defined in the select, so they cannot be used at the same select level. The normal solution is to repeat the expression or to use a subquery, so the alias is known. However, the logic for your query doesn't look write. I suspect it should be something more like this:
SELECT CONCATE_WS, ',', lat.postmeta.meta_value, lng.postmeta.meta_value) ,
lat.postmeta.meta_value AS latitude,
lng.meta_value AS longitude,
. . .
FROM `wp_umkreissuche_posts` posts JOIN
`wp_umkreissuche_postmeta` lat
ON posts.ID = postmeta.post_id AND posts.post_type = 'adresses' AND lat.meta_key = 'latitude' JOIN
`wp_umkreissuche_postmeta` lng
ON posts.ID = postmeta.post_id AND posts.post_type = 'adresses' AND lng.meta_key = 'longitude'
HAVING distance < 0.5
ORDER BY postmeta.post_id, distance ASC;
Note: you can use the having without a group by in MySQL. It then behaves like a where but it allows column aliases.

Answer 2

You cannot use an alias name in another field in the same query unless you use a subquery or join.
Use
(SUBSTRING_INDEX(GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ","),",",1)
instead of latitude.
Try this way:
SELECT GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ","),
SUBSTRING_INDEX(GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ","),",",1) AS latitude,
SUBSTRING_INDEX(SUBSTRING_INDEX(GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ","),",",2),",",-1) AS longitude,
( 6371 * acos( cos( radians(52.2734487789) ) * cos( radians(latitude ) ) * cos( radians(longitude ) - radians(10.5438383386) ) + sin( radians(52.2734487789) ) * sin( radians((SUBSTRING_INDEX(GROUP_CONCAT(TRIM(postmeta.meta_value) SEPARATOR ","),",",1)) ) ) ) AS distance
FROM wp_umkreissuche_posts AS posts, wp_umkreissuche_postmeta AS postmeta
WHERE posts.post_type="adresses" AND posts.ID=postmeta.post_id AND postmeta.meta_key="latitude" OR posts.post_type="adresses" AND posts.ID=postmeta.post_id AND postmeta.meta_key="longitude"
GROUP BY postmeta.post_id HAVING distance < 0.5
ORDER BY postmeta.post_id, distance ASC