I have several queries which are similar and only differ in the conditional clause. I am trying to combine all the queries into a single one.
The first query looks like this:
First query:
SELECT pages.title,
YEAR(page_revisions.date) AS year,
MONTH(page_revisions.date) AS MONTH,
COUNT(revid) AS Cadmin_edits
FROM page_revisions
INNER JOIN pages ON page_revisions.title=pages.title
WHERE userid!=0 AND admin=1 AND pages.ns=0
GROUP BY year, MONTH
ORDER BY page_revisions.title, year, MONTH;
+--------------+------+-------+--------------+
| title | year | MONTH | Cadmin_edits |
+--------------+------+-------+--------------+
| Bangalore | 2002 | 11 | 4 |
| Bangalore | 2003 | 2 | 2 |
| Bangalore | 2003 | 5 | 1 |
| Bangalore | 2003 | 6 | 6 |
| Bangalore | 2003 | 8 | 4 |
| Bangalore | 2003 | 9 | 3 |
| Bangalore | 2003 | 10 | 2 |
| Bart Simpson | 2002 | 9 | 4 |
| Bart Simpson | 2007 | 3 | 33 |
| Bart Simpson | 2007 | 7 | 15 |
| Bart Simpson | 2008 | 11 | 19 |
| Batman | 2001 | 12 | 5 |
The second query is very similar, only difference is in the conditional wikip_member=1 instead of admin.
Second query:
SELECT pages.title,
YEAR(page_revisions.date) AS year,
MONTH(page_revisions.date) AS MONTH,
COUNT(revid) AS Wpart_edits
FROM page_revisions
INNER JOIN pages ON page_revisions.title=pages.title
WHERE userid!=0 AND wikip_member=1 AND pages.ns=0
GROUP BY year, MONTH
ORDER BY page_revisions.title, year, MONTH;
+------------------------------------------+------+-------+-------------+
| title | year | MONTH | Wpart_edits |
+------------------------------------------+------+-------+-------------+
| 1906 Florida Keys hurricane | 2011 | 10 | 266 |
| 1906 Florida Keys hurricane | 2011 | 11 | 108 |
| 1906 Florida Keys hurricane | 2012 | 2 | 66 |
| 1969 race riots of Singapore | 2007 | 6 | 124 |
| 1969 race riots of Singapore | 2008 | 2 | 143 |
| 1969 race riots of Singapore | 2009 | 1 | 151 |
| 1980 Winter Olympics | 2003 | 8 | 3 |
| 1980 Winter Olympics | 2003 | 10 | 7 |
| 1980 Winter Olympics | 2004 | 3 | 16 |
| Babe Ruth | 2004 | 5 | 22 |
| Babe Ruth | 2004 | 7 | 21 |
| Bangalore | 2002 | 11 | 6 |
| Bangalore | 2003 | 2 | 2 |
| Bangalore | 2004 | 2 | 9 |
Essentially what I need the output to look like is like this:
Intended output:
+------------------------------------------+------+-------+--------+-------+
| title | year | MONTH | Cadmin | Wpart |
+------------------------------------------+------+-------+--------+-------+
| 1906 Florida Keys hurricane | 2011 | 10 | 0 | 266 |
| 1906 Florida Keys hurricane | 2011 | 11 | 0 | 108 |
| 1906 Florida Keys hurricane | 2012 | 2 | 0 | 66 |
| 1969 race riots of Singapore | 2007 | 6 | 0 | 124 |
| 1969 race riots of Singapore | 2008 | 2 | 0 | 143 |
| 1969 race riots of Singapore | 2009 | 1 | 0 | 151 |
| 1980 Winter Olympics | 2003 | 8 | 0 | 3 |
| 1980 Winter Olympics | 2003 | 10 | 0 | 7 |
| 1980 Winter Olympics | 2004 | 3 | 0 | 16 |
| Babe Ruth | 2004 | 4 | 0 | 7 |
| Babe Ruth | 2004 | 8 | 0 | 21 |
| Bangalore | 2002 | 11 | 4 | 6 |
| Bangalore | 2003 | 2 | 2 | 2 |
| Bangalore | 2003 | 5 | 1 | 0 |
| Bangalore | 2003 | 6 | 6 | 0 |
| Bangalore | 2003 | 8 | 4 | 0 |
| Bangalore | 2003 | 9 | 3 | 0 |
| Bangalore | 2003 | 10 | 2 | 0 |
| Bangalore | 2004 | 2 | 0 | 9 |
Which would be a combination of the queries. Basically getting the COUNT of the revisions for each month and showing a 0 when no revisions that matches the conditions are found for that month. I have tried a few methods such as UNION, SUBSELECT, but didn’t have any success. The UNION didn’t seem to work as intended and the SUBSELECT took 5 hours to run for only 128 rows.
UNION ATTEMPT:
SELECT pages.title,
YEAR(page_revisions.date) AS year,
MONTH(page_revisions.date) AS MONTH,
COUNT(revid) AS Cadmin,
null AS Wpart
FROM page_revisions
INNER JOIN pages ON page_revisions.title=pages.title
WHERE userid!=0 AND admin=1 AND pages.ns=0
UNION
SELECT pages.title,
mid( page_revisions.date, 1, 4) AS year,
mid(page_revisions.date, 6, 2) AS MONTH,
null as Cadmin,
COUNT(revid) AS Wpart_edits
FROM page_revisions
INNER JOIN pages ON page_revisions.title=pages.title
WHERE userid!=0 AND wikip_member=1 AND pages.ns=0
GROUP BY year, MONTH
ORDER BY title, year, MONTH;
SUBSELECT ATTEMPT:
SELECT pages.title,
YEAR(page_revisions.date) AS year,
MONTH(page_revisions.date) AS MONTH,
(SELECT COUNT(revid) AS Cadmin_edits FROM page_revisions WHERE YEAR(page_revisions.date)=year and MONTH(page_revisions.date)= month and userid!=0 AND admin=1)
FROM page_revisions
INNER JOIN pages ON page_revisions.title=pages.title
WHERE pages.ns=0
GROUP BY year, MONTH
ORDER BY pages.title, year, MONTH;
Any help pointing me in the right direction would be greatly appreciated. This is for my final presentation which is due on Friday and this is the last query I need to wrap everything together.
In MySql (and many other SQL dialects), you can join to a subselect. This should perform better, as the engine will run the query once to produce a single result set, as opposed to running a subquery that is part of the select clause once per row of the initial results.
So, you’d try something like this:
If this were Oracle or Sql Server, I would have recommended a couple of common table expressions for the subqueries, as they would allow you to remove the subquery from the main query, making the full query easier to understand.