MySQL queries

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MySQL queries allow you to pull data from the Toolserver's replicated databases.

Contents

[edit] Database layout

The database layout is available at the MediaWiki wiki: mw:Manual:Database layout.

There are also two commands you can use to view the layout. SHOW TABLES will show the available tables in a database. DESCRIBE table_name will show the available columns in a specific table.

[edit] Clusters

The various databases are stored in clusters. The clusters are named with a preceding S and a digit, e.g., S1, S2, etc. A table of this information is available here: Wiki server assignments.

[edit] Data storage

There are a few tricks to how data is stored in the various tables.

  1. Page titles use underscores and never include the namespace prefix.
  2. User names use spaces, not underscores.
  3. Namespaces are integers. A key to the integers is available here. The localized names for the namespaces can be obtained from the Toolserver database.

[edit] Views

The Toolserver has exact replicas of Wikimedia's databases, however, certain information is restricted to Toolserver users using MySQL views.

For example, the user table does not show things like user_password or user_email to Toolserver users.

[edit] Accessing the data

There are a variety of ways to access the databases. From the command line, a shell script exists that automatically selects the correct cluster for you.

$ sql enwiki_p

This command will connect to the appropriate cluster (in this case, S1) and give you a MySQL prompt where you can run queries.

$ sql enwiki_p < test-query.sql > test-query.txt

This command takes a .sql file that contains your query, selects the appropriate cluster, runs the query, and outputs to a text file. The advantage here is that it doesn't add lines around the data (making a table), it instead outputs the data in a tab-delimited format.

$ sql enwiki_p < test-query.sql | gzip >test-query.txt.gz

This command does the same thing as the command above, but after outputting to a text file, it gzips the data. This can be very helpful if you're dealing with large amounts of data.

The sql shell script is a wrapper around the mysql command. Either method works, though the sql shell script selects the appropriate cluster for you.

If you wish to use the mysql command directly, a sample query would look like this:

$ mysql -h sql-s1 enwiki_p -e "DESCRIBE `user`;"

The -h option tells MySQL which host to access (in this case sql-s1). The -e option tells MySQL to echo the results of the query to the terminal. You can also have MySQL output the results to a file.

$ mysql -h sql-s1 enwiki_p < test-query.sql > test-query.txt

[edit] Writing queries

Because the Toolserver database is read-only, nearly all of the queries you will want to run will be SELECT queries.

SELECT * FROM `user`;

This query selects all columns from the user table. More information about MySQL queries are available below (in the example queries) and in the MySQL manual.

Queries end in a semi-colon (;). If you want to cancel the query, end it in \c. If you want to output in a non-table format, use \G.

[edit] Toolserver database

The "toolserver" database contains metadata about the various wikis and databases. It consists of four tables: language, namespace, namespacename, and wiki.

More information: Toolserver database


[edit] Example queries

w:en:Wikipedia:Database reports (and its equivalents in other languages) contain many useful examples.

[edit] Atypical log entries

SELECT
  user_name,
  log_namespace,
  ns_name,
  log_timestamp,
  log_action,
  log_title,
  log_comment
FROM logging
JOIN toolserver.namespace
ON log_namespace = ns_id
AND dbname = 'enwiki_p'
JOIN `user`
ON log_user = user_id
WHERE log_type='delete'
AND log_action != 'restore'
AND log_action != 'delete';

Explanation: This pulls log entries from the deletion log that aren't restore or delete actions.

[edit] Broken redirects

See also source code of Special:BrokenRedirects
SELECT
  p1.page_namespace,
  ns_name,
  p1.page_title
FROM redirect AS rd
JOIN page p1
ON rd.rd_from = p1.page_id
  JOIN toolserver.namespace
  ON p1.page_namespace = ns_id
  AND dbname = 'enwiki_p'
LEFT JOIN page AS p2
ON rd_namespace = p2.page_namespace
AND rd_title = p2.page_title
WHERE rd_namespace >= 0
AND p2.page_namespace IS NULL
ORDER BY p1.page_namespace ASC;

Explanation: This pulls all broken redirects.

[edit] Cross-namespace redirects

SELECT
  pt.page_namespace,
  pf.page_title,
  ns_name,
  rd_title
FROM redirect, page AS pf, page AS pt
JOIN toolserver.namespace
ON pt.page_namespace = ns_id
AND dbname = 'enwiki_p'
WHERE pf.page_namespace = 0
AND rd_title = pt.page_title
AND rd_namespace = pt.page_namespace
AND pt.page_namespace != 0
AND rd_from = pf.page_id
AND pf.page_namespace = 0;

Explanation: This pulls redirects from (Main) to any other namespace.

[edit] Deleted red-linked categories

SELECT
  cattmp.cl_to,
  cattmp.cl_count,
  user_name,
  log_timestamp,
  log_comment
FROM logging
JOIN `user` ON log_user = user_id
JOIN
(SELECT
   cl_to,
   COUNT(cl_to) AS cl_count
 FROM categorylinks
 LEFT JOIN page ON cl_to = page_title
 AND page_namespace = 14
 WHERE page_title IS NULL
 GROUP BY cl_to) AS cattmp
ON log_title = cattmp.cl_to
WHERE log_namespace = 14
AND log_type = "delete"
AND log_timestamp = (SELECT
                       MAX(log_timestamp)
                     FROM logging AS LAST
                     WHERE log_namespace = 14
                     AND cattmp.cl_to = LAST.log_title);

Explanation: This pulls non-existent used categories that have previously been deleted.

[edit] Empty categories

SELECT
  page_title,
  page_len
FROM categorylinks
RIGHT JOIN page ON cl_to = page_title
WHERE page_namespace = 14
AND page_is_redirect = 0
AND cl_to IS NULL
AND NOT EXISTS (SELECT
                  1
                FROM categorylinks
                WHERE cl_from = page_id
                AND cl_to = 'Wikipedia_category_redirects')
AND NOT EXISTS (SELECT
                  1
                FROM categorylinks
                WHERE cl_from = page_id
                AND cl_to = 'Disambiguation_categories')
AND NOT EXISTS (SELECT
                  1
                FROM templatelinks
                WHERE tl_from = page_id
                AND tl_namespace = 10
                AND tl_title = 'Empty_category');

Explanation: This pulls empty categories that aren't in specific categories and don't transclude a specific template.

[edit] Fully-protected articles with excessively long expiries

SELECT
  page_is_redirect,
  page_title,
  user_name,
  logs.log_timestamp,
  pr_expiry,
  logs.log_comment
FROM page
JOIN page_restrictions ON page_id = pr_page
AND page_namespace = 0
AND pr_type = 'edit'
AND pr_level = 'sysop'
AND pr_expiry > DATE_FORMAT(DATE_ADD(NOW(),INTERVAL 1 YEAR),'%Y%m%d%H%i%s')
AND pr_expiry != 'infinity'
LEFT JOIN logging AS logs ON logs.log_title = page_title
                         AND logs.log_namespace = 0
                         AND logs.log_type = 'protect'
LEFT JOIN `user` ON logs.log_user = user_id 
WHERE CASE WHEN (NOT ISNULL(log_timestamp)) 
  THEN log_timestamp = (SELECT MAX(LAST.log_timestamp)
                        FROM logging AS LAST 
                        WHERE log_title = page_title 
                        AND log_namespace = 0
                        AND log_type = 'protect') 
  ELSE 1 END;

Explanation: Articles that are fully-protected from editing for more than one year.

[edit] Excessively long IP blocks

SELECT
  ipb_address,
  ipb_by_text,
  ipb_timestamp,
  ipb_expiry,
  ipb_reason
FROM ipblocks
WHERE ipb_expiry > DATE_FORMAT(DATE_ADD(NOW(),INTERVAL 2 YEAR),'%Y%m%d%H%i%s')
AND ipb_expiry != "infinity"
AND ipb_user = 0;

Explanation: Blocks of anonymous users that are longer than two years (but not indefinite).

[edit] Indefinitely fully-protected articles

SELECT
  page_is_redirect,
  page_title,
  user_name,
  logs.log_timestamp,
  logs.log_comment
FROM page
JOIN page_restrictions ON page_id = pr_page
AND page_namespace = 0
AND pr_type = 'edit'
AND pr_level = 'sysop'
AND pr_expiry = 'infinity'
LEFT JOIN logging AS logs ON logs.log_title = page_title
                         AND logs.log_namespace = 0
                         AND logs.log_type = 'protect'
LEFT JOIN `user` ON logs.log_user = user_id 
WHERE CASE WHEN (NOT ISNULL(log_timestamp)) 
  THEN log_timestamp = (SELECT MAX(LAST.log_timestamp)
                        FROM logging AS LAST 
                        WHERE log_title = page_title 
                        AND log_namespace = 0
                        AND log_type = 'protect') 
  ELSE 1 END;

Explanation: Articles indefinitely fully-protected from editing.

[edit] Long pages

SELECT
  page_namespace,
  ns_name,
  page_title,
  page_len
FROM page
JOIN toolserver.namespace
ON page_namespace = ns_id
AND dbname = 'enwiki_p'
WHERE page_len > 175000
AND page_title NOT LIKE "%/%"
ORDER BY page_namespace ASC;

Explanation: Pages over 175,000 bytes in length; excludes titles with "/" in them (to avoid archives, etc.).

[edit] Redirects obscuring page content

SELECT
  page_namespace,
  ns_name,
  page_title,
  page_len
FROM page
JOIN toolserver.namespace
ON page_namespace = ns_id
AND dbname = 'enwiki_p'
WHERE page_is_redirect = 1
HAVING page_len > 449
ORDER BY page_namespace ASC;

Explanation: Redirects with large page lengths. This usually indicates there is text below the redirect that should not be there.

[edit] Mistagged non-free content

SELECT
  DISTINCT(enwiki_p.page.page_title),
  commonswiki_p.image.img_name
FROM enwiki_p.image, commonswiki_p.image, enwiki_p.categorylinks, enwiki_p.page
WHERE enwiki_p.image.img_sha1 = commonswiki_p.image.img_sha1
AND enwiki_p.page.page_title = enwiki_p.image.img_name
AND enwiki_p.categorylinks.cl_from = enwiki_p.page.page_id
AND enwiki_p.categorylinks.cl_to = 'All_non-free_media'
AND enwiki_p.image.img_sha1 != 'phoiac9h4m842xq45sp7s6u21eteeq1';

Explanation: This pulls files on a local wiki that are in non-free category, but also exist at Commons. This indicates that either the local image or the Commons image should be deleted. It excludes the SHA1 empty string due to bad database rows.

[edit] Pages with the most revisions

SELECT
  page_namespace,
  ns_name,
  page_title,
  COUNT(*)
FROM revision
JOIN page ON page_id = rev_page
JOIN toolserver.namespace ON page_namespace = ns_id
AND dbname = 'enwiki_p'
GROUP BY page_namespace, page_title
ORDER BY COUNT(*) DESC
LIMIT 1000;

Explanation: This pulls the pages with the most revisions. On large wikis, it can take several hours (or days) to run.

[edit] Page counts by namespace

SELECT
  page_namespace,
  ns_name,
  MAX(notredir),
  MAX(redir)
FROM (
  SELECT page.page_namespace,
         IF( page_is_redirect, COUNT(page.page_namespace), 0 ) AS redir,
         IF( page_is_redirect, 0, COUNT(page.page_namespace)) AS notredir
  FROM page
  GROUP BY page_is_redirect, page_namespace
  ORDER BY page_namespace, page_is_redirect
) AS pagetmp
JOIN toolserver.namespace ON page_namespace = ns_id AND dbname = 'enwiki_p'
GROUP BY page_namespace;

Explanation: This pulls the number of redirects and non-redirects in each namespace.

[edit] Orphaned talk pages

SELECT
  p1.page_namespace,
  ns_name,
  p1.page_title
FROM page AS p1
JOIN toolserver.namespace
ON p1.page_namespace = ns_id
AND dbname = 'enwiki_p'
WHERE p1.page_title NOT LIKE "%/%"
AND p1.page_namespace NOT IN (0,2,3,4,6,8,9,10,12,14,16,18,100,102,104)
AND CASE WHEN p1.page_namespace = 1
  THEN NOT EXISTS (SELECT
                     1
                   FROM page AS p2
                   WHERE p2.page_namespace = 0
                   AND p1.page_title = p2.page_title)
  ELSE 1 END
AND CASE WHEN p1.page_namespace = 5
  THEN NOT EXISTS (SELECT
                     1
                   FROM page AS p2
                   WHERE p2.page_namespace = 4
                   AND p1.page_title = p2.page_title)
  ELSE 1 END
AND CASE WHEN p1.page_namespace = 7
  THEN NOT EXISTS (SELECT
                     1
                   FROM page AS p2
                   WHERE p2.page_namespace = 6
                   AND p1.page_title = p2.page_title)
  AND NOT EXISTS (SELECT
                    1
                  FROM commonswiki_p.page AS p2
                  WHERE p2.page_namespace = 6
                  AND p1.page_title = p2.page_title)
  ELSE 1 END
AND CASE WHEN p1.page_namespace = 11
  THEN NOT EXISTS (SELECT
                     1
                   FROM page AS p2
                   WHERE p2.page_namespace = 10
                   AND p1.page_title = p2.page_title)
  ELSE 1 END
AND CASE WHEN p1.page_namespace = 13
  THEN NOT EXISTS (SELECT
                     1
                   FROM page AS p2
                   WHERE p2.page_namespace = 12
                   AND p1.page_title = p2.page_title)
  ELSE 1 END
AND CASE WHEN p1.page_namespace = 15
  THEN NOT EXISTS (SELECT
                     1
                   FROM page AS p2
                   WHERE p2.page_namespace = 14
                   AND p1.page_title = p2.page_title)
  ELSE 1 END
AND CASE WHEN p1.page_namespace = 17
  THEN NOT EXISTS (SELECT
                     1
                   FROM page AS p2
                   WHERE p2.page_namespace = 16
                   AND p1.page_title = p2.page_title)
  ELSE 1 END
AND CASE WHEN p1.page_namespace = 101
  THEN NOT EXISTS (SELECT
                     1
                   FROM page AS p2
                   WHERE p2.page_namespace = 100
                   AND p1.page_title = p2.page_title)
  ELSE 1 END
AND p1.page_id NOT IN (SELECT
                         page_id
                       FROM page
                       JOIN templatelinks
                       ON page_id = tl_from
                       WHERE tl_title="G8-exempt"
                       AND tl_namespace = 10)
AND p1.page_id NOT IN (SELECT
                         page_id
                       FROM page
                       JOIN templatelinks
                       ON page_id = tl_from
                       WHERE tl_title="Go_away"
                       AND tl_namespace = 10)
AND p1.page_id NOT IN (SELECT
                         page_id
                       FROM page
                       JOIN templatelinks
                       ON page_id = tl_from
                       WHERE tl_title="Rtd"
                       AND tl_namespace = 10);

Explanation: This (very, very hackishly) pulls all pages in the talk namespaces that don't have a corresponding subject-space page. It JOINs against Commons to ensure that File_talk: pages are truly orphaned. It also has some en.wiki-specific template checks in it.

[edit] Ownerless pages in the user space

SELECT
  page_namespace,
  ns_name,
  page_title,
  page_len
FROM page
JOIN toolserver.namespace
ON page_namespace = ns_id
AND dbname = `enwiki_p`
LEFT JOIN `user`
ON user_name = REPLACE(page_title, '_', ' ')
WHERE page_namespace IN (2,3)
AND page_is_redirect = 0
AND page_title NOT LIKE "%/%"
AND page_title NOT RLIKE "(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)"
AND user_name IS NULL;

Explanation: This pulls all User: and User_talk: pages not belonging to a registered user. Pages belonging to an anonymous user are excluded.

[edit] Polluted categories

SELECT DISTINCT
  cl_to
FROM categorylinks AS cat
JOIN page AS pg1
ON cat.cl_from = pg1.page_id
WHERE page_namespace = 2
AND EXISTS (SELECT
              1
            FROM page AS pg2
            JOIN categorylinks AS cl
            ON pg2.page_id = cl.cl_from
            WHERE pg2.page_namespace = 0
            AND cat.cl_to = cl.cl_to)
AND cl_to NOT IN (SELECT
                    page_title
                  FROM page
                  JOIN templatelinks
                  ON tl_from = page_id
                  WHERE page_namespace = 14
                  AND tl_namespace = 10
                  AND tl_title = 'Pollutedcat')
LIMIT 250;

Explanation: This pulls categories that contain pages in the (Main) namespace and the User: namespace. Generally categories hold one or the other.

[edit] Categories categorized in red-linked categories

SELECT
  page_title,
  cl_to
FROM page
JOIN
(SELECT
   cl_to,
   cl_from
 FROM categorylinks
 LEFT JOIN page ON cl_to = page_title
 AND page_namespace = 14
 WHERE page_title IS NULL) AS cattmp
ON cattmp.cl_from = page_id
WHERE page_namespace = 14;

Explanation: This pulls categories categorized in red-linked categories.

[edit] Articles containing red-linked files

SELECT
  page_title,
  il_to
FROM page
JOIN imagelinks
ON page_id = il_from
WHERE (NOT EXISTS(
 SELECT
   1
 FROM image
 WHERE img_name = il_to))
AND (NOT EXISTS(
 SELECT
   1
 FROM commonswiki_p.page
 WHERE page_title = il_to
 AND page_namespace = 6))
AND page_namespace = 0;

Explanation: This pulls articles that contain red-linked images. It checks both Commons and the local wiki.

[edit] Self-categorized categories

SELECT
  page_title,
  cat_pages,
  cat_subcats
FROM page
JOIN categorylinks ON cl_to = page_title
RIGHT JOIN category
ON cat_title = page_title
WHERE page_id = cl_from
AND page_namespace = 14;

Explanation: This pulls self-categorized categories.

[edit] Uncategorized categories

SELECT
  page_title,
  page_len,
  cat_pages,
  rev_timestamp,
  rev_user_text
FROM revision
JOIN
(SELECT
   page_id,
   page_title,
   page_len,
   cat_pages
 FROM category
 RIGHT JOIN page ON cat_title = page_title
 LEFT JOIN categorylinks ON page_id = cl_from
 WHERE cl_from IS NULL
 AND page_namespace = 14
 AND page_is_redirect = 0) AS pagetmp
ON rev_page = pagetmp.page_id
AND rev_timestamp = (SELECT MAX(rev_timestamp)
                     FROM revision AS LAST 
                     WHERE LAST.rev_page = pagetmp.page_id);

Explanation: This pulls uncategorized categories.

[edit] Pages in a specific category using a specific template

SELECT
  page_title
FROM page
JOIN templatelinks
ON tl_from = page_id
JOIN categorylinks
ON cl_from = page_id
WHERE cl_to = "Living_people"
AND tl_namespace = 10
AND tl_title = "Fact"
AND page_namespace = 0
LIMIT 500;

Explanation: This pulls pages that are in a specific category and are using a specific template.

[edit] Top edit timestamp for a category of users

SELECT
  rev_user_text,
  rev_timestamp
FROM revision
JOIN (SELECT
        page_title
      FROM page
      JOIN categorylinks
      ON cl_from = page_id
      WHERE cl_to = 'Category_name_goes_here'
      AND page_namespace = 2
      AND page_title NOT LIKE '%/%') AS cltmp
ON REPLACE(cltmp.page_title, '_', ' ') = rev_user_text
WHERE rev_timestamp = (SELECT
                         MAX(rev_timestamp)
                       FROM revision
                       WHERE rev_user_text = REPLACE(cltmp.page_title, '_', ' '));

Explanation: This will take the user pages that do not contain a forward slash ("/") in "Category_name_goes_here" and get the top edit timestamp for each user.

[edit] Top pages by in a specific namespace for a specific user

SELECT
  `page_title`,
  COUNT(*)
FROM `revision`
JOIN `page`
ON `page_id` = `rev_page`
JOIN `user` 
ON `user_id` = `rev_user`
WHERE `user_name` = 'User name'
AND `page_namespace` = 4
GROUP BY `page_title`
ORDER BY COUNT(*) DESC
LIMIT 25;

Explanation: This will pull the page titles of a the most-edited pages by a specific user in a specific namespace.

[edit] Number of deletions per day for a specific user

SELECT
  DATE( CONCAT( YEAR( log_timestamp), "-", MONTH( log_timestamp ), "-", DAY( log_timestamp ) ) ) AS DAY,
  COUNT(log_timestamp) AS deletions
FROM logging
JOIN `user`
ON log_user = user_id
WHERE user_name = 'User name'
AND log_type = 'delete'
AND log_action = 'delete'
GROUP BY DAY;

Explanation: This will group the number of deletions per day by a specific user.

[edit] Number of deletions per day

SELECT
  DATE(CONCAT(YEAR(log_timestamp),"-",MONTH(log_timestamp),"-",DAY(log_timestamp))) AS DAY,
  COUNT(log_id) AS deletions
FROM logging_ts_alternative
WHERE log_type = 'delete'
AND log_action = 'delete'
GROUP BY DAY;

Explanation: This will pull the number of deletions per day on a given wiki.

[edit] Most common deletion summaries

SELECT
  log_comment,
  COUNT(log_id)
FROM logging_ts_alternative
WHERE log_type = 'delete'
AND log_action = 'delete'
GROUP BY log_comment
ORDER BY COUNT(log_id) DESC;

Explanation: This will pull the most common deletion summaries on a given wiki.

[edit] Most common deletion summaries for a specific user

SELECT
  log_comment AS reason,
  COUNT(*) AS uses
FROM logging
JOIN `user`
ON log_user = user_id
WHERE user_name = 'User name'
AND log_type = 'delete'
AND log_action = 'delete'
GROUP BY reason
ORDER BY uses DESC
LIMIT 25;

Explanation: This will pull the most commonly used deletion summaries for a specific user.

[edit] Most common edit summaries for a specific user

SELECT
  rev_comment,
  COUNT(*)
FROM revision
WHERE rev_user_text = 'User name'
GROUP BY rev_comment
ORDER BY COUNT(*) DESC
LIMIT 25;

Explanation: This will pull the most commonly used edit summaries for a specific user.

[edit] Number of revisions per day

SELECT
  DATE(CONCAT(YEAR(rev_timestamp),"-",MONTH(rev_timestamp),"-",DAY(rev_timestamp))) AS DAY,
  COUNT(rev_timestamp) AS revisions
FROM revision
GROUP BY DAY;

Explanation: This will pull the number of (non-deleted) revisions to a particular wiki and group the numbers by day.

[edit] Number of revision per day by a specific user

SELECT
  DATE(CONCAT(YEAR(rev_timestamp),"-",MONTH(rev_timestamp),"-",DAY(rev_timestamp))) AS DAY,
  COUNT(rev_timestamp) AS revisions
FROM revision
WHERE rev_user_text = 'User name'
GROUP BY DAY;

Explanation: This will pull the number of (non-deleted) revisions by a specific user per day.

[edit] File description pages without an associated file

SELECT
  page_title
FROM page
WHERE NOT EXISTS (SELECT
                    img_name
                  FROM image
                  WHERE img_name = page_title)
AND NOT EXISTS (SELECT
                  img_name
                FROM commonswiki_p.image
                WHERE img_name = page_title)
AND page_namespace = 6
AND page_is_redirect = 0
LIMIT 1000;

Explanation: This will pull file description pages that do not have an associated file, either locally or in the Commons repo.

[edit] Files without an associated file description page

SELECT
  img_name
FROM image
WHERE NOT EXISTS (SELECT
                    page_title
                  FROM page
                  WHERE img_name = page_title
                  AND page_namespace = 6)
AND NOT EXISTS (SELECT
                  page_title
                FROM commonswiki_p.page
                WHERE img_name = page_title
                AND page_namespace = 6);

Explanation: This will pull files that have no associated file description page, either locally or in the Commons repo.

[edit] File description pages containing no templates

SELECT
  ns_name,
  page_title,
  page_len
FROM page
JOIN toolserver.namespace
ON dbname = 'enwiki_p'
AND ns_id = page_namespace
LEFT JOIN templatelinks
ON tl_from = page_id
WHERE NOT EXISTS (SELECT
                    img_name
                  FROM commonswiki_p.image
                  WHERE img_name = page_title)
AND page_namespace = 6
AND page_is_redirect = 0
AND tl_from IS NULL
LIMIT 800;

Explanation: This will pull file description pages containing no templates that do not have an associated file description page in the Commons repo.

[edit] File description pages containing no templates or categories

SELECT
  ns_name,
  page_title,
  page_len
FROM page
JOIN toolserver.namespace
ON dbname = 'enwiki_p'
AND ns_id = page_namespace
LEFT JOIN templatelinks
ON tl_from = page_id
LEFT JOIN categorylinks
ON cl_from = page_id
WHERE NOT EXISTS (SELECT
                    img_name
                  FROM commonswiki_p.image
                  WHERE img_name = page_title)
AND page_namespace = 6
AND page_is_redirect = 0
AND tl_from IS NULL
AND cl_from IS NULL
LIMIT 800;

Explanation: This will pull file description pages containing no templates or categories that do not have an associated file description page in the Commons repo.

[edit] Links on a particular page

SELECT
  pl_namespace,
  pl_title
FROM page
JOIN pagelinks
ON pl_from = page_id
WHERE page_namespace = 0
AND page_title = 'Don\'t_poke_the_bear';

Explanation: This will pull the names of the links on a particular page. For example, the text of the "Don't poke the bear" page contains the link "[[bear]]" so the output of this query will list "Bear" as a result.

[edit] Links to a particular page

SELECT
  page_namespace,
  page_title
FROM page
JOIN pagelinks
ON pl_from = page_id
WHERE pl_namespace = 0
AND pl_title = 'Don\'t_poke_the_bear';

Explanation: This will pull the names of the links to a particular page. This is the equivalent of Special:WhatLinksHere. For example, the page "What not to do" may contain the link "[[Don't poke the bear]]"; this query would output "What not to do" as a result.

[edit] Pages containing 0 page links

SELECT
  page_namespace,
  page_title
FROM page
LEFT JOIN pagelinks
ON pl_from = page_id
WHERE pl_namespace IS NULL
LIMIT 1;

Explanation: This will pull pages that contain 0 page links. This will not account for things like image links, template links, category links, or external links.

[edit] Pages with 0 links to them

SELECT
  page_namespace,
  page_title
FROM page
LEFT JOIN pagelinks
ON pl_title = page_title
AND pl_namespace = page_namespace
WHERE pl_namespace IS NULL
LIMIT 1;

Explanation: This will pull pages that have 0 links to them (Special:WhatLinksHere would be empty!).

[edit] Short pages with a single author (excluding user pages and redirects)

SELECT
  CONCAT(ns_name, ':', page_title),
  page_len
FROM page
JOIN toolserver.namespace
ON page_namespace = ns_id
AND dbname = 'enwiki_p'
LEFT JOIN templatelinks
ON tl_from = page_id
WHERE page_len < 50
AND page_is_redirect = 0
AND page_namespace NOT IN (2, 3)
AND tl_from IS NULL
AND (SELECT
       COUNT(DISTINCT rev_user_text)
     FROM revision
     WHERE rev_page = page_id) = 1
ORDER BY page_len ASC

Explanation: This will list short pages with a single author (excluding user pages and redirects).

[edit] Unused templates

SELECT
  CONCAT('Template:', page_title)
FROM page
LEFT JOIN templatelinks
ON page_namespace = tl_namespace
AND page_title = tl_title
WHERE page_namespace = 10
AND tl_from IS NULL

Explanation: This will pull unused templates.

[edit] Broken image links

SELECT
  CONCAT("* [[", IF (page_namespace = 0, page_title, concat(":", ns_name, ":", page_title)), "]]",
              " - [[:Bilde:", il_to, "]]") AS links 
FROM imagelinks
JOIN page
ON page_id = il_from 
JOIN toolserver.namespace
ON ns_id = page_namespace
AND dbname = "nowiki_p" 
LEFT JOIN image AS I
ON I.img_name = il_to 
LEFT JOIN commonswiki_p.image AS J
ON J.img_name = il_to 
WHERE I.img_name IS NULL
AND J.img_name IS NULL /* SLOW_OK */;

Explanation: List references to images that are not present locally nor on Commons (nowiki).

[edit] Revision counting for specific user till specific time

SELECT
  COUNT(*)
FROM revision
WHERE rev_user_text = 'User name'
AND rev_timestamp < '20120327000000';

Explanation: Return the number of revisions by a specific user up to a certain time.

[edit] Log count in recent time by users not in group

A query like this outputs the users with:

  • the most log actions of the kind specified (in the example, patrol/patrol minus autopatrolled edits),
  • in the interval specified (in the example, last 24 months),
  • excluding users in some user groups (in the example, sysop and rollbacker).
/* SLOW_OK adapted from Krinkle, bug 25799 */
 
SELECT
    COUNT(*) AS counter,
    user_name,
    user_editcount,
    GROUP_CONCAT(DISTINCT ug_group SEPARATOR ", ")
 
FROM logging log
 
JOIN USER us
  ON log.log_user = us.user_id
 
JOIN user_groups ug
  ON log.log_user = ug.ug_user
 
WHERE ug.ug_user NOT IN
  (SELECT DISTINCT user_groups.ug_user
   FROM user_groups
   WHERE ug_group = 'sysop'
   OR ug_group = 'rollbacker'
  )
AND log.log_type = 'patrol'
AND log.log_action = 'patrol'
AND log.log_timestamp > ( NOW() - INTERVAL 24 MONTH )  
AND ( log.log_params LIKE '%"6::auto";i:0%'
OR    log.log_params LIKE '%\n0' /* not autopatrolled */ )
GROUP BY log.log_user
 
ORDER BY counter DESC
LIMIT 50;

In wikis where "patrol" right is given to all users, the example query can be used to find active patrollers who would be likely candidates for additional rights (like autropatrolled, rollbacker, sysop etc. depending on the wiki's configuration).

[edit] Redirects with more than one revision

SELECT
  page_title,
  rd_namespace,
  rd_title,
  COUNT(*) AS edits
FROM revision
INNER JOIN page
ON rev_page = page_id
INNER JOIN redirect
ON rev_page = rd_from
WHERE page_namespace = 0
AND page_is_redirect = 1
GROUP BY page_title
HAVING COUNT(*) > 1;

Explanation: This query lists redirect pages with more than one revision.

[edit] Short non-disambiguation pages

SELECT
  page_title
FROM page
WHERE page_namespace = 0
AND page_is_redirect = 0
AND page_id NOT IN (SELECT
                      tl_from
                    FROM templatelinks
                    WHERE tl_title = 'Disambiguation'
                    AND tl_namespace = 10)
ORDER BY page_len ASC
LIMIT 1000;

Explanation: This query lists 1000 non-disambiguation short pages.

[edit] List of external links

SELECT
  COUNT(*),
  TRIM(LEADING 'www.' FROM SUBSTRING_INDEX(SUBSTRING_INDEX(el_to, '/', 3),'/',-1)) AS site
FROM externallinks, page
WHERE el_from = page_id
AND page_namespace = 0
GROUP BY 2
HAVING COUNT(*) > 10 
ORDER BY 1;

Explanation: This query compiles a list of external links (from the main namespace) grouped by website.

[edit] List of external links from all wikis

List of external links to a given domain from all namespaces on all Wikimedia projects; requires iterating over wikis, with a bash script in the example, syntax like ./extlinks.sh http://meta.wikimedia.org (outputs DB name, page title, linked URL).

#!/bin/bash
WIKIS=$(mysql -BN -h sql -e 'SELECT dbname FROM toolserver.wiki WHERE domain IS NOT NULL AND is_closed = 0;')
 
for dbname in $WIKIS;
do
        echo $dbname
        echo "
/* SLOW_OK */
SELECT CONCAT(ns_name, ':', page_title), el_to
FROM externallinks
JOIN page ON el_from = page_id
JOIN toolserver.namespacename ON dbname = '$dbname' AND ns_is_favorite AND ns_id = page_namespace
WHERE el_to LIKE '$1%'
-- " | mysql -h ${dbname/_/-}.rrdb.toolserver.org -BcN $dbname
        # mysql switches
        # -c  Prevent comment stripping, need to prevent the query killer
        # -N  No column name heading
        # -B Bare formatted / -t Table formatted / -H HTML output / -X XML output
done;

[edit] List of interwiki links from all wikis

As above; use lowercase interwikiki prefix, like ./iwlinks.sh meatball.

#!/bin/bash
WIKIS=$(mysql -BN -h sql -e 'SELECT dbname FROM toolserver.wiki WHERE domain IS NOT NULL AND is_closed = 0;')
 
for dbname in $WIKIS;
do
        echo $dbname
        echo "
/* SLOW_OK */
SELECT CONCAT(ns_name, ':', page_title), CONCAT('$1:', iwl_title)
FROM iwlinks
JOIN page ON iwl_from = page_id
JOIN toolserver.namespacename ON dbname = '$dbname' AND ns_is_favorite AND ns_id = page_namespace
WHERE iwl_prefix = '$1'
-- " | mysql -h ${dbname/_/-}.rrdb.toolserver.org -BcN $dbname
        # mysql switches
        # -c  Prevent comment stripping, need to prevent the query killer
        # -N  No column name heading
        # -B Bare formatted / -t Table formatted / -H HTML output / -X XML output
done;


[edit] User Activity

Activity of registered users, as edits per day. This query filters out flagged bots but might still miss though.

SELECT 
    rev_user, 
    COUNT(*) / ( unix_timestamp(MAX(rev_timestamp)) - unix_timestamp(MIN(rev_timestamp)) ) * 86400.0 AS edits_per_day
FROM revision LEFT JOIN user_groups
ON rev_user = user_id 
WHERE (user_id IS NULL OR ug_group <> 'bot') AND rev_user > 0 
GROUP BY rev_user;

[edit] Article Size

This query works on the WMF Slave db

 SELECT
  rev_page                      AS page_id,
  COUNT(*)                      AS revisions,
  COUNT(DISTINCT rev_user_text) AS editors,
  SUM(rev_len)                  AS SIZE
 FROM revision
 GROUP BY rev_page;

[edit] Top 10 Articles in Size

This query works on the WMF Slave db

 SELECT
  rev_page,
  COUNT(DISTINCT rev_user_text),
  SUM(rev_len)
  page_title AS title,
 FROM revision
 INNER JOIN page
  page_id = rev_page
 GROUP BY rev_page
 ORDER BY SUM(rev_len) DESC
 LIMIT 10;

[edit] Top links, red and blue

This query works on the WMF Slave db

SELECT 
 pl_title, 
 COUNT(*), 
 page_id
FROM enwiki.pagelinks 
LEFT JOIN enwiki.page ON 
 pl_title = page_title 
WHERE 
 pl_namespace = 0 AND
 page_namespace = 0 
GROUP BY 1

[edit] First messages to users, by tool/bot used (if any)

SELECT
 page_id, page_title, rev_comment,rev_user, rev_user_text,
 CAST(rev_timestamp AS datetime) AS rev_timestamp, CAST(user_registration AS datetime) AS user_registration,
 datediff(rev_timestamp,user_registration) AS datediff_msg_reg, timediff(rev_timestamp,user_registration) AS timediff_msg_reg,
 DATE_FORMAT(user_registration,"%Y-%m-%d") AS user_reg_ymd, DATE_FORMAT(rev_timestamp,"%Y-%m-%d") AS first_msg_ymd, user_id,
 (rev_comment LIKE '%WP:HG%' OR rev_comment LIKE '%WP:HUGGLE%') AS huggle, (rev_comment LIKE '%WP:TW%') tw,
 (rev_comment LIKE '%igloo|GLOO]]%') AS gloo,
 (rev_comment LIKE '%WP:STiki%') AS stiki,
 (rev_user_text LIKE 'ClueBot%') AS cluebot,
 (rev_user_text = 'XLinkBot') AS xlinkbot,
 (rev_user_text = 'CorenSearchBot') AS corenbot,
 (rev_user_text LIKE 'BetacommandBot%') AS betacommandbot,
 (rev_user_text LIKE '%Bot') AS bot,
 (rev_user_text LIKE page_title) AS SELF
FROM enwiki.page 
LEFT JOIN enwiki.revision ON page_id = rev_page
LEFT JOIN enwiki.USER ON REPLACE(page_title,"_"," ") = user_name
WHERE page_namespace = 3 AND LOCATE('/',page_title) = 0 
GROUP BY page_id;

[edit] Number of registrations per day

 SELECT DATE_FORMAT(log_timestamp,"%Y-%m-%d"), COUNT(*)
 FROM enwiki.logging
 WHERE log_action = 'create' AND log_type='newusers'
 GROUP BY 1
 ORDER BY log_timestamp;

[edit] Automated tool and bot edits

UPDATE rev_table SET tool = 'rollback' WHERE rev_comment RLIKE "(Reverted ([0-9]+ )?edits by \[\[Special:Contributions/[^\|]+\|[^]]+\]\] \(\[\[User talk:[^\|]+\|talk\]\]\) to last version by .+)";
UPDATE rev_table SET tool = 'undo' WHERE rev_comment LIKE "Undid revision%";
UPDATE rev_table SET tool = 'huggle' WHERE rev_comment LIKE '%WP:HG%' OR rev_comment LIKE '%WP:HUGGLE%';
UPDATE rev_table SET tool = 'huggle' WHERE rev_comment RLIKE "(Message re\. \[\[[^]]+\]\])|(Level [0-9]+ warning re\. \[\[[^]]+\]\])";
UPDATE rev_table SET tool = 'twinkle' WHERE rev_comment LIKE '%WP:TW%';
UPDATE rev_table SET tool = 'friendly' WHERE rev_comment LIKE '%WP:FRIENDLY%' OR rev_comment LIKE '%WP:Friendly%';
UPDATE rev_table SET tool = 'vandalproof' WHERE rev_comment LIKE '%WP:VPRF%' OR rev_comment LIKE '%WP:VandalProof%' OR rev_comment LIKE '%VandalProof|VandalProof%' OR rev_comment LIKE '%WP:VP2%' OR rev_comment LIKE '%WP:VandalProof%';
UPDATE rev_table SET tool = 'stiki' WHERE rev_comment LIKE '%|STiki]]%';
UPDATE rev_table SET tool = 'npwatcher' WHERE rev_comment LIKE '%|NPWatcher%';
UPDATE rev_table SET tool = 'vandalsniper' WHERE rev_comment LIKE '%|VandalSniper%';
UPDATE rev_table SET tool = 'wikimonitor' WHERE rev_comment LIKE '%m:WikiMonitor%';
UPDATE rev_table SET tool = 'mwt' WHERE rev_comment LIKE '%MWT|MWT]]%';
UPDATE rev_table SET tool = 'awb' WHERE rev_comment LIKE '%AWB|AWB]]%' OR rev_comment LIKE '%AutoWikiBrowser%';
UPDATE rev_table SET tool = 'cluebot' WHERE LOWER(CAST(rev_user_text AS CHAR)) LOWER LIKE 'cluebot%';
UPDATE rev_table SET tool = 'antivandalbot' WHERE rev_user_text = 'AntiVandalBot';
UPDATE rev_table SET tool = 'orphanbot' WHERE rev_user_text = 'OrphanBot'; 
UPDATE rev_table SET tool = 'pseudobot' WHERE rev_user_text = 'PseudoBot';
UPDATE rev_table SET tool = 'voabot' WHERE rev_user_text LIKE 'VoABot%';
UPDATE rev_table SET tool = 'martinbot' WHERE rev_user_text = 'MartinBot';
UPDATE rev_table SET tool = 'stbot' WHERE rev_user_text LIKE 'STBot%';
UPDATE rev_table SET tool = 'sqlbot' WHERE rev_user_text = 'SQLbot';
UPDATE rev_table SET tool = 'tawkerbot' WHERE rev_user_text LIKE 'Tawkerbot%';
UPDATE rev_table SET tool = 'sinebot' WHERE rev_user_text = 'SineBot';
UPDATE rev_table SET tool = 'csdwarnbot' WHERE rev_user_text = 'CSDWarnBot';
UPDATE rev_table SET tool = 'antispambot' WHERE rev_user_text = 'AntiSpamBot';

[edit] Determining Huggle and Twinkle messages types by revision comment

UPDATE rev_table SET tool = 'huggle' WHERE rev_comment LIKE '%WP:HG%' OR rev_comment LIKE '%WP:HUGGLE%';
UPDATE rev_table SET tool = 'twinkle' WHERE rev_comment LIKE '%WP:TW%';
 
UPDATE rev_table SET msg_type = 'warning', msg_type_sub='level1' WHERE rev_comment LIKE 'Message re.%' AND tool = 'huggle';
UPDATE rev_table SET msg_type = 'warning', msg_type_sub='level2' WHERE rev_comment LIKE 'Level 2 warning%' AND tool = 'huggle';
UPDATE rev_table SET msg_type = 'warning', msg_type_sub='level3' WHERE rev_comment LIKE 'Level 3 warning%' AND tool = 'huggle';
UPDATE rev_table SET msg_type = 'warning', msg_type_sub='level4' WHERE rev_comment LIKE 'Level 4 warning%' AND tool = 'huggle';
 
UPDATE rev_table SET msg_type = 'warning', msg_type_sub='level1' WHERE rev_comment LIKE 'General note:%' AND tool = 'twinkle';
UPDATE rev_table SET msg_type = 'warning', msg_type_sub='level2' WHERE rev_comment LIKE 'Caution:%' AND tool = 'twinkle';
UPDATE rev_table SET msg_type = 'warning', msg_type_sub='level3' WHERE rev_comment LIKE 'Warning:%' AND tool = 'twinkle';
UPDATE rev_table SET msg_type = 'warning', msg_type_sub='level4' WHERE rev_comment LIKE 'Final warning:%' AND tool = 'twinkle';
 
UPDATE rev_table SET msg_type = 'deletion', msg_type_sub = 'csd' WHERE rev_comment LIKE 'Notification: speedy deletion%' AND tool = 'twinkle';
UPDATE rev_table SET msg_type = 'deletion', msg_type_sub = 'tag' WHERE rev_comment LIKE 'Notification: tagging for deletion%' AND tool = 'twinkle';
UPDATE rev_table SET msg_type = 'deletion', msg_type_sub = 'prop' WHERE rev_comment LIKE 'Notification: proposed deletion%' AND tool = 'twinkle';
UPDATE rev_table SET msg_type = 'notification', msg_type_sub = 'listing' WHERE rev_comment LIKE 'Notification: listing at%' AND tool = 'twinkle';
UPDATE rev_table SET msg_type = 'talkback' WHERE rev_comment LIKE 'Talkback%' AND tool = 'twinkle';
UPDATE rev_table SET msg_type = 'notification', msg_type_sub = 'blocked' WHERE rev_comment LIKE 'You have been%' AND tool = 'twinkle';
UPDATE rev_table SET msg_type = 'notification', msg_type_sub = 'blocked' WHERE rev_comment LIKE 'Your IP address has been blocked%' AND tool = 'twinkle';
UPDATE rev_table SET msg_type = 'welcome' WHERE rev_comment LIKE 'Added welcome%' AND tool = 'twinkle';
 
UPDATE rev_table SET msg_type = 'welcome' WHERE rev_comment LIKE 'Welcoming%' AND tool = 'huggle';
UPDATE rev_table SET msg_type = 'deletion', msg_type_sub = 'csd' WHERE rev_comment LIKE 'Notification: Speedy deletion%' AND tool = 'huggle';
UPDATE rev_table SET msg_type = 'deletion', msg_type_sub = 'prop' WHERE rev_comment LIKE 'Notification: Proposed deletion%' AND tool = 'huggle';
UPDATE rev_table SET msg_type = 'notification', msg_type_sub = 'blocked' WHERE rev_comment LIKE 'Notification: Blocked%' AND tool = 'huggle';

[edit] Deletion count by day (Mainspace)

SELECT
DATE( log_timestamp ) AS DATE,
COUNT( log_id ) AS deletions
FROM logging
WHERE log_action='delete'
AND log_namespace =0
GROUP BY DATE( log_timestamp )

[edit] List of users with a certain log action (not) among global users

For instance, a query to have a list of autocreated accounts (which have an entry in autocreate log) which are not known by CentralAuth (bugzilla:61876):

SELECT
  log_title,
  log_user,
  log_timestamp
FROM logging
JOIN USER ON logging.log_action = 'autocreate'
AND log_timestamp > 20130831000000
AND logging.log_user = USER.user_id /* user_name and lu_name are normalised, log_* contains e.g. underscores */
WHERE USER.user_name NOT IN (
  SELECT lu_name
  FROM centralauth_p.localuser lu
  WHERE lu.lu_wiki = 'metawiki'
);

[edit] Editors of a page by edit count

Something like this can be used for instance to quickly list users who (don't) meet requirements for voting in a poll, though usually requirements are about more than edit count (cf. accounteligibility tool for complex examples).

SELECT DISTINCT
  rev_user_text,
  user_editcount
FROM revision
LEFT JOIN USER /* This will leave rows for unregistered users too */
ON revision.rev_user = USER.user_id
WHERE revision.rev_page = 1000 /* Insert page ID here, e.g. from action=info */
ORDER BY user_editcount DESC;

[edit] Regular expressions

[edit] Is an IP address

This query matches 999.999.999.999 as well as valid addresses like 129.47.61.5

REGEXP '^[0-9]{1,3}[.][0-9]{1,3}[.][0-9]{1,3}[.][0-9]{1,3}$'

[edit] Most edited pages in last month

SELECT rc_title, COUNT(*) AS num_edits
FROM recentchanges 
WHERE rc_namespace = 0 
GROUP BY 1 ORDER BY 2 DESC
LIMIT 25;

[edit] See also

Administration
In other languages
Personal tools