加入和GROUP_CONCAT数据顺序问题 [英] Trouble with joining and the order of GROUP_CONCAT data

问题描述

我有几个表，我想从中合并数据.我从 User 表中选择基本信息，并希望从 User_Status、User_Sex_Info、User_Personal_Info 和表中加入数据媒体.

我在处理 Media 表中的数据时遇到问题，因为该表可以容纳同一用户的多条记录，但我只想显示最多 6 条记录(按顺序排列), 在任何情况下，一张 Type 1 图像，然后最多五张 Type 2 图像).其他表每个用户只有一行.我目前有下表来选择数据:

<预><代码>选择User.u_UserName、User.u_UserMail、User.u_UserRegistration、Status.us_PaymentStatus,Sex.us_Gender, Sex.us_Interest,Personal.up_Name、Personal.up_Dob、Personal.up_City、Personal.up_Province、UserMedia.m_Id, UserMedia.m_Type, SUBSTRING_INDEX(GROUP_CONCAT(康卡特(UserMedia.m_Type, ':', UserMedia.m_File)ORDER BY UserMedia.m_Type = 1, UserMedia.m_Date DESC SEPARATOR '-'),'-',6) 作为用户文件从用户作为用户JOIN User_Status AS 状态 ON Status.User_u_UserId = User.u_UserIdJOIN User_Sex_Info AS Sex ON Sex.User_u_UserId = User.u_UserIdLEFT JOIN User_Personal_Info AS Personal ON Personal.User_u_UserId = User.u_UserIdLEFT JOIN Media AS UserMedia ON UserMedia.User_u_UserId = User.u_UserId哪里 User.u_UserId = :uIdGROUP BY UserMedia.m_Id

除媒体文件外，此方法适用于所有数据.输出是 18-profile.jpg 而我期待 18-profile.jpg-18-2.jpg-18-2.jpg-18-4.jpg-18-5.jpg-18-6.jpg

Media 表如下所示:

如果不存在`Media`，则创建表(`m_Id` int(11) NOT NULL AUTO_INCREMENT,`m_Type` enum('1','2','3') NOT NULL DEFAULT '3' COMMENT '1 = 个人资料图片\n2 = 用户图片\n3 = 内容图片',`m_File` varchar(255) 非空，`m_Date` 日期时间非空，`User_u_UserId` int(11) 非空，PRIMARY KEY (`m_Id`,`User_u_UserId`),唯一键`m_id_UNIQUE`(`m_Id`)，唯一键`m_name_UNIQUE`(`m_File`)，密钥`fk_Media_User1_idx`(`User_u_UserId`)) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=9 ;插入`媒体`(`m_Id`、`m_Type`、`m_File`、`m_Date`、`User_u_UserId`)值(2, '1', '18-profile.jpg', '2013-07-30 00:00:00', 18),(3, '2', '18-1.jpg', '2013-07-30 00:00:00', 18),(4, '2', '18-2.jpg', '2013-07-30 00:00:00', 18),(5, '2', '18-3.jpg', '2013-07-30 00:00:00', 18),(6, '2', '18-4.jpg', '2013-07-30 00:00:00', 18),(7, '2', '18-5.jpg', '2013-07-30 00:00:00', 18),(8, '2', '18-6.jpg', '2013-07-30 00:00:00', 18);

我是否忽略了什么?我不明白为什么它不起作用.

编辑我创建了一个带有查询的 SQL Fiddle 并在七行中显示了我的数据.我不明白为什么当我在本地运行它时它不再显示任何行

编辑 2显然问题出在 GROUP_CONCAT 中，因为 phpmyadmin 显示的结果与 SQL Fiddle 相同.我去看看

解决了！我将数据分组到错误的参数上，我需要按 User.u_UserId 分组.感谢观看！

解决方案

更改

GROUP BY UserMedia.m_Id

到

GROUP BY User.u_userId

m_Id 对于每个 Media 行都是唯一的，因此您没有将任何内容组合在一起.

I'm having a few tables from which i want to merge the data. I select basic information from the User table and want to join data from the tables User_Status, User_Sex_Info, User_Personal_Info and Media.

I'm encountering troubles with the data from the Media table, since this table can hold up many records of the same user, but i only want to display a maximum of six records (in order, In any case, one Type 1 image, followed by a maximum of five Type 2 images). The other tables only have one row of each user. I currently have the following table to select the data:

SELECT
    User.u_UserName, User.u_UserMail, User.u_UserRegistration, 
        Status.us_PaymentStatus, 
        Sex.us_Gender, Sex.us_Interest, 
            Personal.up_Name, Personal.up_Dob, Personal.up_City, Personal.up_Province, 
            UserMedia.m_Id, UserMedia.m_Type, SUBSTRING_INDEX(
                GROUP_CONCAT(
                    CONCAT(
                        UserMedia.m_Type, ':', UserMedia.m_File
                    )
                    ORDER BY UserMedia.m_Type = 1, UserMedia.m_Date DESC SEPARATOR '-'
                ),'-',6
            ) AS userFile   
FROM User AS User
    JOIN User_Status AS Status ON Status.User_u_UserId = User.u_UserId
    JOIN User_Sex_Info AS Sex ON Sex.User_u_UserId = User.u_UserId
        LEFT JOIN User_Personal_Info AS Personal ON Personal.User_u_UserId = User.u_UserId
        LEFT JOIN Media AS UserMedia ON UserMedia.User_u_UserId = User.u_UserId
WHERE User.u_UserId = :uId
GROUP BY UserMedia.m_Id

This one works fine on all the data, except for the media files. The output is 18-profile.jpg while i was expecting 18-profile.jpg-18-2.jpg-18-2.jpg-18-4.jpg-18-5.jpg-18-6.jpg

The Media table looks like this:

CREATE TABLE IF NOT EXISTS `Media` (
  `m_Id` int(11) NOT NULL AUTO_INCREMENT,
  `m_Type` enum('1','2','3') NOT NULL DEFAULT '3' COMMENT '1 = Profile picture\n2 = User picture\n3 = Content image',
  `m_File` varchar(255) NOT NULL,
  `m_Date` datetime NOT NULL,
  `User_u_UserId` int(11) NOT NULL,
  PRIMARY KEY (`m_Id`,`User_u_UserId`),
  UNIQUE KEY `m_id_UNIQUE` (`m_Id`),
  UNIQUE KEY `m_name_UNIQUE` (`m_File`),
  KEY `fk_Media_User1_idx` (`User_u_UserId`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=9 ;

INSERT INTO `Media` (`m_Id`, `m_Type`, `m_File`, `m_Date`, `User_u_UserId`) VALUES
(2, '1', '18-profile.jpg', '2013-07-30 00:00:00', 18),
(3, '2', '18-1.jpg', '2013-07-30 00:00:00', 18),
(4, '2', '18-2.jpg', '2013-07-30 00:00:00', 18),
(5, '2', '18-3.jpg', '2013-07-30 00:00:00', 18),
(6, '2', '18-4.jpg', '2013-07-30 00:00:00', 18),
(7, '2', '18-5.jpg', '2013-07-30 00:00:00', 18),
(8, '2', '18-6.jpg', '2013-07-30 00:00:00', 18);

Do i overlook something? I don't see why it isn't working.

EDIT I created a SQL Fiddle with the query and that shows my data in seven rows. I don't understand why it's not displaying any more rows when i run it locally

EDIT 2 Apparently the problem is in the GROUP_CONCAT since phpmyadmin shows the same result as the SQL Fiddle. I'm going to look at that

SOLVED IT! I grouped the data on the wrong parameter, i needed to group by User.u_UserId. Thanks for looking!

解决方案

Change

GROUP BY UserMedia.m_Id

to

GROUP BY User.u_userId

m_Id is unique for each Media row, so you weren't grouping anything together.

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