mysql - SQL:完全外部连接不工作

Question

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Answer 1

MySQL 没有语法关键字FULL OUTER JOIN。您必须使用 LEFT 和 RIGHT JOIN 的组合来获得完整连接。

SELECT  t0.hugot_id                     as hugot_id,
        t0.upvotes                      as upvotes,
        t1.comment_count                as comment_count
FROM
    hugot_votes_stats as t0
LEFT JOIN
    hugot_comment_stats as t1
ON
    t0.hugot_id = t1.hugot_id

UNION ALL 

SELECT  t0.hugot_id                     as hugot_id,
        t0.upvotes                      as upvotes,
        t1.comment_count                as comment_count
FROM
    hugot_votes_stats as t0
RIGHT JOIN
    hugot_comment_stats as t1
ON
    t0.hugot_id = t1.hugot_id