再次需要关于加入表格的帮助

Question

我问了一个关于 MySQL 请求的问题，我的帖子可以在这里找到：Need help about joining tables

现在我有另一个与此相关的问题，所以在我的页面上，我列出了来自数据库的票，我的请求是：

"SELECT
    glpi_tickets.id,
    glpi_tickets.name,
    GROUP_CONCAT(
            CASE WHEN glpi_tickets_users.type = 1 THEN 
            CONCAT(glpi_users.firstname, ' ', glpi_users.realname)
        END) AS creator,
    GROUP_CONCAT(
        CASE WHEN glpi_tickets_users.type = 1 THEN 
            CONCAT(glpi_tickets_users.users_id)
        END) AS creator_id,
    GROUP_CONCAT(
        CASE WHEN glpi_tickets_users.type = 2 THEN 
            CONCAT(glpi_users.firstname, ' ', glpi_users.realname)
        END) AS users,
    GROUP_CONCAT(
        CASE WHEN glpi_tickets_users.type = 2 THEN 
            CONCAT(glpi_tickets_users.users_id)
        END) AS users_id,
    glpi_tickets.date,
    glpi_tickets.priority,
    glpi_tickets.date_mod,
    glpi_itilcategories.completename,
    glpi_tickets.status,
    glpi_tickets.users_id_lastupdater,
    GROUP_CONCAT(
        CASE WHEN glpi_tickets.users_id_lastupdater = glpi_users.id THEN
            CONCAT(glpi_users.firstname, ' ', glpi_users.realname) 
        END SEPARATOR '<br>') AS last_updater,
    glpi_tickets.content
    FROM
        glpi_tickets
    JOIN glpi_tickets_users ON glpi_tickets_users.tickets_id = glpi_tickets.id
    JOIN glpi_users ON glpi_users.id = glpi_tickets_users.users_id
    JOIN glpi_itilcategories ON glpi_itilcategories.id = glpi_tickets.itilcategories_id
    GROUP BY
        glpi_tickets.id"

结果如下：

[ID][Title][creator][date created][priority][category][status][date modified][assigned to][last update by]
[125][helpdesk test][admin][29-01-2013 21:09][low][messaging][new][30-01-2013 17:52][Tony][admin]

对于每张工单，creator - creator_id 和 users - users_id 可以包含多个 ID 和名称。

现在我想在另一个页面中显示用户信息，我使用了相同的请求，但 WHERE glpi_users.id = ? 从 users.php?id=x 获取 id

除了创建者和用户之外，一切都很好，因为WHERE glpi_users.id = x 只选择一个人。

我想要一种显示方式，就像之前的请求一样，提前致谢

编辑：尝试了 GolezTrols 解决方案，但它不起作用，这是我的查询：

"SELECT
                        glpi_tickets.id,
                        glpi_tickets.name,
                        GROUP_CONCAT(
                            CASE WHEN glpi_tickets_users.type = 1 THEN 
                                CONCAT(glpi_users.firstname, ' ', glpi_users.realname)
                            END) AS creator,
                        GROUP_CONCAT(
                            CASE WHEN glpi_tickets_users.type = 1 THEN 
                                CONCAT(glpi_tickets_users.users_id)
                            END) AS creator_id,
                        GROUP_CONCAT(
                            CASE WHEN glpi_tickets_users.type = 2 THEN 
                                CONCAT(glpi_users.firstname, ' ', glpi_users.realname)
                            END) AS users,
                        GROUP_CONCAT(
                            CASE WHEN glpi_tickets_users.type = 2 THEN 
                                CONCAT(glpi_tickets_users.users_id)
                            END) AS users_id,
                        glpi_tickets.date,
                        glpi_tickets.priority,
                        glpi_tickets.date_mod,
                        glpi_itilcategories.completename,
                        glpi_tickets.status,
                        glpi_tickets.users_id_lastupdater,
                        GROUP_CONCAT(
                            CASE WHEN glpi_tickets.users_id_lastupdater = glpi_users.id THEN
                                CONCAT(glpi_users.firstname, ' ', glpi_users.realname) 
                            END SEPARATOR '<br>') AS last_updater,
                        glpi_tickets.content
                    FROM
                        glpi_tickets
                        JOIN glpi_tickets_users ON glpi_tickets_users.tickets_id = glpi_tickets.id
                        JOIN glpi_users ON glpi_users.id = glpi_tickets_users.users_id
                        JOIN glpi_itilcategories ON glpi_itilcategories.id = glpi_tickets.itilcategories_id
                    WHERE
                       exists (
                            SELECT 
                              'x' 
                            FROM
                              glpi_tickets_users
                            WHERE
                            glpi_tickets_users.tickets_id = glpi_tickets.id AND
                            glpi_tickets_users.id = ? AND
                            glpi_tickets_users.type = 1)
                    GROUP BY
                        glpi_tickets.id"

几乎所有时间它根本没有显示票证，有时它显示票证但与用户无关，例如，如果我尝试users.php?id=1536，它将显示由用户 870 创建的票证号 789负责这张票的用户 1180 和 1632...

Answer 1

您应该检查用户是否与问题相关，而不是过滤确切的用户 ID，如下所示：

select
  t.title,
  group_concat(
    case when tu.type = 1 then 
      concat(u.firstname, ' ', u.lastname)
    end) as creator,
  t.priority,
  t.date,
  group_concat(
    case when tu.type = 2 then 
      concat(u.firstname, ' ', u.lastname)
    end SEPARATOR ' - ') as users
from
  tickets t
  inner join tickets_users tu on tu.ticketid = t.id
  inner join users u on u.id = tu.userid
where 
  exists (
    select 
      'x' 
    from 
      tickets_users tu2 
    where 
      tu2.ticketid = t.id and 
      tu2.userid = <youruserid> and 
      tu2.type = 1)
group by
  t.id;

对于<youruserid>，您可以填写您想要的用户ID。此查询将返回该用户报告的所有问题（类型 = 1）。但是对于所有这些问题，仍然会返回所有相关用户，因此您的查询结果仍然是完整的。