[英]Mysql: join 2 table with latest record only
i had 2 table, tableA and tableB looking like this:我有 2 张桌子,tableA 和 tableB,看起来像这样:
tableA:表A:
tableB:表B:
i manage to get the latest record by auto increment id by using the following sql for tableA and tableB:我设法通过对 tableA 和 tableB 使用以下 sql 自动递增 id 来获取最新记录:
SELECT *
FROM tableA
WHERE id IN (SELECT MAX(id) AS id
FROM tableA
GROUP BY social_num)
SELECT *
FROM tableB
WHERE id IN (SELECT MAX(id) AS id
FROM tableB
GROUP BY social_num)
how to join them together, so that, i get the latest record on tableA and latest record on tableB link by social_num?如何将它们连接在一起,以便我通过 social_num 获得 tableA 上的最新记录和 tableB 链接上的最新记录? i tried following sql, it work:
我尝试按照 sql,它工作:
SELECT *
FROM tableA
LEFT JOIN tableB ON tableA.social_num = tableB.social_num
WHERE tableA.id IN (SELECT MAX(id) AS id
FROM tableA
GROUP BY social_num)
AND
tableB.id IN (SELECT MAX(id) AS id
FROM tableB
GROUP BY social_num)
but how do i show all of other user from tableA togather as well, like Morris Q但是我如何同时显示 tableA 中的所有其他用户,例如Morris Q
DDL Information DDL信息
CREATE TABLE `tableA` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`fullname` varchar(255) DEFAULT NULL,
`social_num` varchar(255) DEFAULT NULL,
`email` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=13 DEFAULT CHARSET=utf8;
/*Data for the table `tableA` */
insert into `tableA`(`id`,`fullname`,`social_num`,`email`) values (1,'David J','1155','davidj@gmail.com'),(2,'Brian H','2244','brianh@gmail.com'),(3,'Hawkins M','6677','hawkins@gmail.com'),(4,'Marry K','7122','marry@gmail.com'),(5,'Utah O','9123','utah@gmail.com'),(6,'James L','1266','james@gmail.com'),(7,'David J','1155','david@hotmail.com'),(8,'Marry K','7122','marry@gmail.com'),(9,'Johnson E','1180','johnson@gmail.com'),(10,'Hawkins M','6677','hawkins@yahoo.com'),(11,'Morris Q','1461','morris@gmail.com'),(12,'David J','1155','david@yahoo.com');
CREATE TABLE `tableB` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`fullname` varchar(255) DEFAULT NULL,
`social_num` varchar(255) DEFAULT NULL,
`phone_num` varchar(255) DEFAULT NULL,
`fav_color` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;
/*Data for the table `tableB` */
insert into `tableB`(`id`,`fullname`,`social_num`,`phone_num`,`fav_color`) values (1,'Brian H','2244','912-112-1231','blue'),(2,'Johnson E','1180','912-221-5512','red'),(3,'David J','1155','812-231-6125','green'),(4,'Utah O','9123','741-661-3125','red'),(5,'Hawkins M','6677','881-331-6612','blue'),(6,'James L','1266','934-513-5132','yellow'),(7,'Brian H','2244','785-513-9821','green'),(8,'David J','1155','960-231-5151','black'),(9,'Hawkins M','6677','135-661-3516','red');
Any help would be great.任何帮助都会很棒。 Thanks
谢谢
Answered by Kondybas at DBA DBA的 Kondybas 回答
SELECT a.*, b.*
FROM
(SELECT MAX(w.id) AS id
, w.social_num
FROM tableA AS w
GROUP BY w.social_num
) AS maxa
LEFT JOIN
(SELECT MAX(z.id) AS id
, z.social_num
FROM tableB AS z
GROUP BY z.social_num
) AS maxb ON maxb.social_num = maxa.social_num
JOIN tableA AS a ON a.id = maxa.id
LEFT JOIN tableB AS b ON b.id = maxb.id
;
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