Question

Can someone please explain me this SQL query. This shows me the popular stores, but it doesn’t works well.

sql = "SELECT t.name, t.slug, tt.count 
FROM ".$wpdb->prefix."terms AS t INNER JOIN ".$wpdb->prefix."term_taxonomy AS tt ON t.term_id = tt.term_id
WHERE 
  tt.taxonomy IN ('$tax_name') 
  AND tt.count > 0 
GROUP BY tt.count DESC 
ORDER BY RAND() LIMIT $the_limit";

Answer 1

For GROUP BY to work, you need to apply some kind of aggregating function to everything you’re not GROUPing BY.

I assume what you want is the total count for each store:

sql = "SELECT t.name, t.slug, sum(tt.count) as count
FROM ".$wpdb->prefix."terms AS t

INNER JOIN ".$wpdb->prefix."term_taxonomy AS tt 
ON t.term_id = tt.term_id

WHERE tt.taxonomy IN ('$tax_name')
GROUP BY tt.term_id
HAVING count > 0";