Test query

Name	Region	categories
Italy	Europe
Mauritania	Africa

SELECT t0.page_id AS `page_id`,t0.value AS `v0`,t1.value AS `v1`,GROUP_CONCAT(categorylinks_t0.cl_to SEPARATOR 0x1E) AS `categories` FROM (SELECT t.value,t.page_id,p.path_no_index,p.path,p.path_parent,p.schema_id FROM `visualdata_text` `t` JOIN `visualdata_props` `p` ON ((p.id=t.prop_id)) WHERE schema_id = '3' AND path_no_index = 'name' ) `t0` LEFT JOIN (SELECT t.value,t.page_id,p.path_no_index,p.path,p.path_parent,p.schema_id FROM `visualdata_text` `t` JOIN `visualdata_props` `p` ON ((p.id=t.prop_id)) WHERE schema_id = '3' AND path_no_index = 'region' ) `t1` ON (((t1.page_id=t0.page_id))) LEFT JOIN `categorylinks` `categorylinks_1` ON (((categorylinks_1.cl_to = 'Test_cat_a'))) JOIN `page` `page_alias` ON ((page_alias.page_id = t0.page_id)) LEFT JOIN `categorylinks` `categorylinks_t0` ON ((t0.page_id = categorylinks_t0.cl_from)) WHERE t0.schema_id = '3' AND ((t0.value IS NOT NULL)) AND ((t0.page_id = categorylinks_1.cl_from)) GROUP BY t0.page_id, t0.value, t1.value LIMIT 100