3

mysql(5.1.36)中关于全连接的问题很多。当然，解决方案是加入工会组合。

我的问题是我有两个这样的临时表：

CREATE TEMPORARY TABLE wConfs
(
    idWorker INT,
    confs SMALLINT
) ENGINE=INNODB;

CREATE TEMPORARY TABLE wRejects
(
    idWorker INT,
    rejects SMALLINT
) ENGINE=INNODB;

JOIN-UNION mix 不能用于完全连接临时表，因为它会导致ERROR 1137 (HY000): Can't reopen table.

我的问题是——在临时表上实现完全连接的最简单的解决方案是什么？

编辑：加入联合组合：

SELECT wc.idWorker, wc.confs, wr.rejects FROM wConfs wc LEFT JOIN wRejects wr 
ON (wr.idWorker = wc.idWorker)
UNION
SELECT wc.idWorker, wc.confs, wr.rejects FROM wConfs wc RIGHT JOIN wRejects wr 
ON (wr.idWorker = wc.idWorker);
4

2 回答 2

5

尝试使用idWorker来自两个表的不同值创建第三个临时表，然后在您的 JOIN-UNION 组合中使用它，例如 -

CREATE TEMPORARY TABLE all_id
  SELECT idWorker FROM wConfs UNION SELECT idWorker FROM wRejects;

SELECT t.idWorker, c.confs, r.rejects FROM all_id t
LEFT JOIN wConfs c
  ON t.idWorker = c.idWorker
LEFT JOIN wRejects r
  ON t.idWorker = r.idWorker;
于 2012-06-12T09:47:31.927 回答
1

我找到了另一种解决方法。我还创建了第三个临时表：

DROP TABLE IF EXISTS wResults;
CREATE TEMPORARY TABLE wResults
(
    idWorker INT PRIMARY KEY,
    rejects SMALLINT,
    confs SMALLINT
) ENGINE=INNODB;

现在我像这样插入行：

INSERT INTO wResults(idWorker, confs)
    SELECT idWorker, confs FROM wConfs;

INSERT INTO wResults(idWorker, rejects)
    SELECT wr.idWorker, wr.rejects FROM wRejects wr
    ON DUPLICATE KEY UPDATE rejects = wr.rejects;

它就像一个魅力。我想如果要插入很多数据 - 它会很慢，但我的表很小。总之谢谢大家！

于 2012-06-12T10:14:41.200 回答