我正在尝试让我的查询返回JSON以在API中使用。我正在使用PostGIS扩展来处理位置信息。 PostGIS扩展程序运行良好,而不是此问题的问题。我只提到这一点,因为查询中有与PostGIS扩展相关的函数。我有JSON文档的这些对象:
这是我的SQL语句:
SELECT c.id, c.name, c.website, c.longdescription, c.description, c.email,
jsonb_agg((SELECT ev FROM (SELECT ev.title, ev.description, ev.longdescription, jsonb_agg((SELECT ed FROM(SELECT ed.startdate, ed.enddate, ed.id WHERE ed.id notnull)ed)) AS dates, ev.id WHERE ev.id notnull)ev)) AS events,
jsonb_agg((SELECT ca FROM (SELECT ct.zip, ca.id, ca.street1, ca.street2, ca.addresstype_id, ST_Y(ca.geopoint::geometry) AS latitude, ST_X(ca.geopoint::geometry) AS longitude WHERE ca.id notnull)ca)) AS addresses
FROM companies c
LEFT JOIN events ev ON ev.company_id = c.id
LEFT JOIN companyaddresses ca ON ca.company_id = c.id
LEFT JOIN cities ct ON ct.id = ca.city_id
LEFT JOIN eventdates ed ON ed.event_id = ev.id
GROUP BY c.id
我有什么想法可以改为不拥有嵌套函数并且仍能得到正确的结果?
答案 0 :(得分:1)
有问题的一行是
jsonb_agg((SELECT ev FROM (SELECT ev.title, ev.description, ev.longdescription, jsonb_agg((SELECT ed FROM(SELECT ed.startdate, ed.enddate, ed.id WHERE ed.id notnull)ed)) AS dates, ev.id WHERE ev.id notnull)ev)) AS events,
如果将jsonb_agg
移动到第二个子查询中,我认为它会起作用。所以改变
jsonb_agg((SELECT ed FROM(SELECT ed.startdate, ed.enddate, ed.id WHERE ed.id notnull)ed)) AS dates
到
(SELECT jsonb_agg(ed) FROM(SELECT ed.startdate, ed.enddate, ed.id WHERE ed.id notnull)ed) AS dates
我不确定这是否有效,但如果您向ed
和ev
表提供CREATE语句,我可以对其进行优化。