我有三张桌子,比如:
parent(id, name)
children(id, data, parent_id, timestamp)
table_votes(id, user_id, child_id)
我想从children
具有特定parent_id
,也显示了发生在table_votes
每个人。
我尝试了以下的方法,但似乎不起作用,我想我错过了所有的行children
没有进入table_votes
SELECT
`children`.`id`,
`children`.`data`,
`children`.`parent_id`,
`children`.`timestamp`,
COUNT(`v`.`children_id`)
FROM `children` LEFT JOIN `table_votes` `v` ON `children`.`id` = `v`.`child_id`
WHERE `children`.`parent_id` = 20 ORDER BY `timestamp` ASC
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