sql连表这三个单独查出来的数据怎样连在一起

Question

-- 已使用
SELECT count(cacwo.id)
FROM carlife_order co
LEFT JOIN carlife_activity_commodity_write_off cacwo ON cacwo.carlife_order_id = co.id
WHERE cacwo.id != '' AND cacwo.type = '1' AND cacwo.carlife_commodity_id = '1'
--已购买
SELECT count(co.id)
FROM carlife_order co
LEFT JOIN carlife_commodity cc ON cc.id = co.carlife_commodity_id
WHERE cc.id = '1'

SELECT cc.name ,cc.id
FROM carlife_commodity cc
LEFT JOIN carlife_activity_commodity cac ON cac.carlife_commodity_id = cc.id
LEFT JOIN carlife_activity ca ON ca.id = cac.carlife_activity_id
WHERE ca.id = '1'

Answer 1

多个表的连接使用join连接，有完全连接、左外/右外连接等等，根据自己的需求，选择合适的命令语句即可，，，相应的命令网上或者数据库书上都有，可以参考！加油！ 祝你成功！ 谢谢