Databases
StackOverflow2013
Postsdbo
POSQL Order and group by
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POSQL Order and group by
    primarykey
    data
    text
    <p>I'm getting a bit lost in making a query that performs a certain look up. I have the first part of the query going, which returns me all accounts that have missing some entries on their account. Now I need to filter this subset further based on their last login attempt.</p> <p>The table structures are as follows:</p> <ul> <li>The users table contains all user information. We only care about users under project_id 33.</li> <li>The users_account_list contains all accounts a user has. We only care about users NOT having an entry for service 50.</li> <li>The users_login_logs contains all login attempts for a user.</li> </ul> <p>The original query I have this this:</p> <pre><code>SELECT u.id, u.login, u.email, u.nickname, b.station_login AS "additionals.station_login", a.id AS "user_account_list.id", a.game_id AS "user_account_list.game_id", a.game_uid AS "user_account_list.game_uid", c.created_at AS "last login" FROM users u LEFT JOIN user_account_list a ON u.id = a.user_id AND a.game_id = 50 LEFT JOIN user_additionals b ON u.id = b.id LEFT JOIN user_login_logs c ON u.id = c.user_id WHERE u.project_id = 33 AND u.verified_at IS NOT NULL AND (a.id IS NULL OR a.game_id IS NULL OR a.game_uid IS NULL) AND (b.station_login IS NULL OR b.station_login = '') ORDER BY c.created_at DESC </code></pre> <p>This returns me all users that have been registered under project_id 33, and do not have an entry for game_id 50, and have no information stored in their additional info table. Optional, but not relevant, Just limits the data returned. It does give me multiple rows per user back , sorted according their latest login date.</p> <p>What I need is to get only 1 row per user returned with their LATEST login date. <em>I tried replacing the ORDER BY with GROUP by u.id</em> but this gives me the oldest result back, not the latest.</p> <p>How can I:</p> <ul> <li>Limit the rows returned to only 1 row per user</li> <li>Make sure the row is based on the latest login attempt of the user.</li> </ul> <p><em>EDIT</em>:</p> <p>This is what the query currently returns:</p> <pre><code>+----+-------+-----------------+----------+---------------------------+----------------------+---------------------------+----------------------------+---------------------+ | id | login | email | nickname | additionals.station_login | user_account_list.id | user_account_list.game_id | user_account_list.game_uid | last login | +----+-------+-----------------+----------+---------------------------+----------------------+---------------------------+----------------------------+---------------------+ | 1 | usrnm | someon@mail.com | Nickname | | NULL | NULL | NULL | 2012-10-19 00:00:00 | | 1 | usrnm | someon@mail.com | Nickname | | NULL | NULL | NULL | 2012-10-18 00:00:00 | | 1 | usrnm | someon@mail.com | Nickname | | NULL | NULL | NULL | 2012-10-17 00:00:00 | +----+-------+-----------------+----------+---------------------------+----------------------+---------------------------+----------------------------+---------------------+ 3 rows in set (0.08 sec) </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. UScoding-bunny
    1. UScoding-bunny
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COWhat RDBMS is this??
      singulars
      1. POSQL Order and group by
      1. USMahmoud Gamal
    2. COmysql database.
      singulars
      1. POSQL Order and group by
      1. UScoding-bunny
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload