I have this query...
SELECT SUM(brownlow_votes) AS votes,
player_id,
player_name,
player_team,
COUNT(*) AS vote_count
FROM afl_brownlow_phantom, afl_playerstats
WHERE player_id=brownlow_player
AND brownlow_match=player_match
GROUP BY player_id
ORDER BY votes DESC LIMIT 50
So "votes" becomes the number of votes a player has, "vote_count" becomes the number of times (matches in which) a player has been voted for. This works fine.
However, I have another column called "brownlow_lock" which is either blank, or 'Y'. How do I get the number of occurances of 'Y'? I know I could solve this changing it to 0 or 1 and just doing a SUM() but I don't want to have to go and edit the tons of pages that are inserting data.
If I have understood you correctly you just need to add
COUNT(CASE WHEN brownlow_lock='Y' THEN 1 END) AS Cnt
to your query
Try using the IF control flow function
SELECT SUM(IF(brownlow_lock='Y',1,0)) lock_count ...
Related
I need to get the amount of users who have rank = player
So far I tried select count(*) as count_players from users where rank = player
I'm not sure where the error is, if only in the tags and query is correct or I'm going about it completely wrong, thanks in advance for the advice!
table: [users]
id
username
password
rank
1
john
$2y$10$zYharAUmf36hVzkYUg87y.avY
player
2
jane
$2y$10$zYhajIUGU89887jhgUg87yKJ8G
admin
COUNT_PLAYERS = 1
Cully below is right, it shouldn't need to be grouped when you're after a single result. You would do the following when you were after it grouped by rank (and you wouldn't do rank='player').
SELECT COUNT(*) AS count_players FROM users WHERE rank='player';
OR SELECT COUNT(*) AS count_players FROM users GROUP BY rank if you wanted it grouped.
Have you tried quoting the rank you're targeting? It's a string, not a variable.
Easiest explained through an example.
A father has children who win races.
How many of a fathers offspring have won a race and how many races in total have a fathers offspring won. (winners and wins)
I can easily figure out the total amount of wins but sometimes a child wins more than one race so to figure out winners I need only sum if the child has won, not all the times it has won.
In the below extract from a query I cannot use Distinct, so this doesn't work
SUM(CASE WHEN r.finish = '1' AND DISTINCT h.runnersid THEN 1 ELSE 0 END ) AS winners,
This also won't work
SUM(SELECT DISTINCT r.runnersid FROM runs r WHERE r.finish='1') AS winners
This works when I need to find the total amount of wins.
SUM(CASE WHEN r.finish = '1' THEN 1 ELSE 0 END ) AS wins,
Here is a sqlfiddle http://sqlfiddle.com/#!2/e9a81/1
Let's take this step by step.
You have two pieces of information you are looking for: Who has won a race, and how many races have they one.
Taking the first one, you can select a distinct runnersid where they have a first place finish:
SELECT DISTINCT runnersid
FROM runs
WHERE finish = 1;
For the second one, you can select every runnersid where they have a first place finish, count the number of rows returned, and group by runnersid to get the total wins for each:
SELECT runnersid, COUNT(*) AS numWins
FROM runs
WHERE finish = 1
GROUP BY runnersid;
The second one actually has everything you want. You don't need to do anything with that first query, but I used it to help demonstrate the thought process I take when trying to accomplish a task like this.
Here is the SQL Fiddle example.
EDIT
As you've seen, you don't really need the SUM here. Because finish represents a place in the race, you don't want to SUM that value, but you want to COUNT the number of wins.
EDIT2
An additional edit based on OPs requirements. The above does not match what OP needs, but I left this in as a reference to any future readers. What OP really needs, as I understand it now, is the number of children each father has that has run a race. I will again explain my thought process step by step.
First I wrote a simple query that pulls all of the winning father-son pairs. I was able to use GROUP BY to get the distinct winning pairs:
SELECT father, name
FROM runs
WHERE finish = 1
GROUP BY father, name;
Once I had done that, I used it is a subquery and the COUNT(*) function to get the number of winners for each father (this means I have to group by father):
SELECT father, COUNT(*) AS numWinningChildren
FROM(SELECT father, name
FROM runs
WHERE finish = 1
GROUP BY father, name) t
GROUP BY father;
If you just need the fathers with winning children, you are done. If you want to see all fathers, I would write one query to select all fathers, join it with our result set above, and replace any values where numWinningChildren is null, with 0.
I'll leave that part to you to challenge yourself a bit. Also because SQL Fiddle is down at the moment and I can't test what I was thinking, but I was able to test those above with success.
I think you want the father name along with the count of the wins by his sons.
select father, count(distinct(id)) wins
from runs where father = 'jack' and finish = 1
group by father
sqlfiddle
I am not sure if this is what you are looking for
Select user_id, sum(case when finish='1' then 1 else 0 end) as total
From table
Group by user_id
I'm getting grey hair by now...
I have a table like this.
ID - Place - Person
1 - London - Anna
2 - Stockholm - Johan
3 - Gothenburg - Anna
4 - London - Nils
And I want to get the result where all the different persons are included, but I want to choose which Place to order by.
For example. I want to get a list where they are ordered by LONDON and the rest will follow, but distinct on PERSON.
Output like this:
ID - Place - Person
1 - London - Anna
4 - London - Nils
2 - Stockholm - Johan
Tried this:
SELECT ID, Person
FROM users
ORDER BY FIELD(Place,'London'), Person ASC "
But it gives me:
ID - Place - Person
1 - London - Anna
4 - London - Nils
3 - Gothenburg - Anna
2 - Stockholm - Johan
And I really dont want Anna, or any person, to be in the result more then once.
This is one way to get the specified output, but this uses MySQL specific behavior which is not guaranteed:
SELECT q.ID
, q.Place
, q.Person
FROM ( SELECT IF(p.Person<=>#prev_person,0,1) AS r
, #prev_person := p.Person AS person
, p.Place
, p.ID
FROM users p
CROSS
JOIN (SELECT #prev_person := NULL) i
ORDER BY p.Person, !(p.Place<=>'London'), p.ID
) q
WHERE q.r = 1
ORDER BY !(q.Place<=>'London'), q.Person
This query uses an inline view to return all the rows in a particular order, by Person, so that all of the 'Anna' rows are together, followed by all the 'Johan' rows, etc. The set of rows for each person is ordered by, Place='London' first, then by ID.
The "trick" is to use a MySQL user variable to compare the values from the current row with values from the previous row. In this example, we're checking if the 'Person' on the current row is the same as the 'Person' on the previous row. Based on that check, we return a 1 if this is the "first" row we're processing for a a person, otherwise we return a 0.
The outermost query processes the rows from the inline view, and excludes all but the "first" row for each Person (the 0 or 1 we returned from the inline view.)
(This isn't the only way to get the resultset. But this is one way of emulating analytic functions which are available in other RDBMS.)
For comparison, in databases other than MySQL, we could use SQL something like this:
SELECT ROW_NUMBER() OVER (PARTITION BY t.Person ORDER BY
CASE WHEN t.Place='London' THEN 0 ELSE 1 END, t.ID) AS rn
, t.ID
, t.Place
, t.Person
FROM users t
WHERE rn=1
ORDER BY CASE WHEN t.Place='London' THEN 0 ELSE 1 END, t.Person
Followup
At the beginning of the answer, I referred to MySQL behavior that was not guaranteed. I was referring to the usage of MySQL User-Defined variables within a SQL statement.
Excerpts from MySQL 5.5 Reference Manual http://dev.mysql.com/doc/refman/5.5/en/user-variables.html
"As a general rule, other than in SET statements, you should never assign a value to a user variable and read the value within the same statement."
"For other statements, such as SELECT, you might get the results you expect, but this is not guaranteed."
"the order of evaluation for expressions involving user variables is undefined."
Try this:
SELECT ID, Place, Person
FROM users
GROUP BY Person
ORDER BY FIELD(Place,'London') DESC, Person ASC;
You want to use group by instead of distinct:
SELECT ID, Person
FROM users
GROUP BY ID, Person
ORDER BY MAX(FIELD(Place, 'London')), Person ASC;
The GROUP BY does the same thing as SELECT DISTINCT. But, you are allowed to mention other fields in clauses such as HAVING and ORDER BY.
I've got a MySQL database with lots of entris of highscores for a game. I would like to get the "personal best" entry with the max value of score.
I found a solution that I thought worked, until I got more names in my database, then it returnes completely different results.
My code so far:
SELECT name, score, date, version, mode, custom
FROM highscore
WHERE score =
(SELECT MAX(score)
FROM highscore
WHERE name = 'jonte' && gamename = 'game1')
For a lot of values, this actually returns the correct value as such:
JONTE 240 2014-04-28 02:52:33 1 0 2053
It worked fine with a few hundred entries, some with different names. But when I added new entries and swapped name to 'gabbes', for the new names I instead get a list of multiple entries. I don't see the logic here as the entries in the database seem quite identical with some differences in data.
JONTE 176 2014-04-28 11:03:46 1 0 63
GABBES 176 2014-04-28 11:09:12 1 0 3087
The above has two entires, but sometimes it may also return 10-20 entries in a row too.
Any help?
If you want the high score for each person (i.e. personal best) you can do this...
SELECT name, max(score)
FROM highscore
WHERE gamename = 'game1'
GROUP BY name
Alternatively, you can do this...
SELECT name, score, date, version, mode, custom
FROM highscore h1
WHERE score =
(SELECT MAX(score)
FROM highscore h2
WHERE name = h1.name && gamename = 'game1')
NOTE: In your SQL, your subclause is missing the name = h1.name predicate.
Note however, that this second option will give multiple rows for the same person if they recorded the same high score multiple times.
The multiple entries are returned because multiple entries have the same high score. You can add LIMIT 1 to get only a single entry. You can choose which entry to return with the ORDER BY clause.
I can tell it best by explaining the query I have, and what I need.
I need to be able to get a group of items from the database, grouped by category, manufacturer, and year made. The groupings need to be sorted based on total amount of items within the group. This part is done with the query below.
Secondly, I need to be able to show an image of the most expensive item out of the group, which is why I use MAX(items.current_price). I thought MAX() gets the ENTIRE row corresponding to the largest column value. I was wrong, as MAX only gets the numeric value of the largest price. So the query doesnt work well for that.
SELECT
items.id,
items.year,
items.manufacturer,
COUNT(items.id) AS total,
MAX(items.current_price) AS price,
items.gallery_url,
FROM
ebay AS items
WHERE
items.primary_category_id = 213
AND
items.year <> ''
AND
items.manufacturer <> ''
AND
items.bad_item <> 1
GROUP BY
items.primary_category_id,
items.manufacturer,
items.year
ORDER BY
total DESC,
price ASC
LIMIT
10
if that doesnt explain it well, the results should be something like this
id 10548
year 1989
manufacturer bowman
total 451
price 8500.00 (The price of the most expensive item in the table/ not the price of item 10548)
gallery_url http://ebay.xxxxx (The image of item 10548)
A little help please. Thanks
I've had this same problem, and I'm fairly certain you have to do two queries (or a subquery, that's a matter of taste).
The first query is like what you have (except id isn't helping you).
The second query uses the GROUP BY fields and one (one!) MAX field to get the id and any other meta-data you need.
I believe this is the implementation, although it's hard to test:
SELECT
items.id,
items.year,
items.manufacturer,
items.gallery_url
FROM
ebay as items
NATURAL JOIN
(
SELECT
COUNT(items.id) AS total,
MAX(items.current_price) AS current_price,
items.primary_category_id,
items.manufacturer,
items.year
FROM
ebay AS items
WHERE
items.primary_category_id = 213
AND
items.year <> ''
AND
items.manufacturer <> ''
AND
items.bad_item <> 1
GROUP BY
items.primary_category_id,
items.manufacturer,
items.year
ORDER BY
total DESC,
price ASC
LIMIT
10
) as bigones
ORDER BY
bigones.total DESC,
bigones.current_price ASC
This documentation may help you understand what's going on:
http://dev.mysql.com/doc/refman/5.1/en/group-by-hidden-columns.html
... all rows in each group should have the same values for the columns that are ommitted from the GROUP BY part. The server is free to return any value from the group, so the results are indeterminate unless all values are the same.