I have a table which stores user items, the two key columns which I would like to use in this query are user_id and item_id. The id field in the example is not needed but just added to show these aren't the only two columns in the table.
----------------------
id user_id item_id
----------------------
1 1 324
2 1 324
3 3 324
4 2 230
5 4 324
The query which I would like to construct should return the top 10 users who have the most items with a specific item id.
So for example if I wanted to run the query against the item ID 324 I should get the following result.
-------------------
user_id item_count
-------------------
1 2
3 1
4 1
2 0
try this
select user_id , count(*) as item_count from table
where item_id = 324 group by user_id order by item_count desc limit 10
limit 10 will show you the top 10 users and order by desc sort from high to low.
However, the above query will not give you the 0 count as per your question. If you really want the zero count you can try this: (assuming your table name is userlist)
SELECT distinct user_id,
(select
count(*) from `userlist`
where user_id=u.user_id and item_id=324
) as item_count FROM `userlist` u
order by item_count desc
I couldn't create the database in my local, but I think this will do the trick
SELECT user_id, COUNT(item_id) as item_count
FROM TABLE_NAME
WHERE item_id = 324
GROUP BY item_id
ORDER BY item_count;
Related
How can I select last (=max) value from column and count of all rows in single query?
ID ITEM_ID VALUE
1 1 100
2 1 101
3 2 201
4 3 333
5 2 222
6 1 111
I want to select last / max value for particular ITEM_ID and count of all rows with this ID.
For ITEM_ID = 1 thus:
VALUE COUNT
111 3
My query is like this:
SELECT (SELECT COUNT(*) FROM table) AS count, (SELECT value FROM table ORDER BY id DESC LIMIT 1) AS value FROM table WHERE item_id = 1 LIMIT 1
It works but looks ... weird. Is there any better (simpler / faster) solution? Thanks
You need to do a GROUP BY on column ITEM_ID while getting the MAX() and COUNT() like
select max(value) as `VALUE`,
count(*) as `COUNT`
from your_table
group by ITEM_ID;
product_id property_id
1 2
1 5
2 2
3 5
I have a mapping table as above. I want to get only product with id =1 if product_id in (2,5). i.e. I want to fetch data if the table contains both 2,5 not the data if it is with property_id only 2 or 5
select group_concat(distinct product_id) product_ids from table where property_id in (2,5)
UPDATE:
The property_id in can be property_id in(2,5,....). I get output from form as 2,5,.... and so on. Its not just for the single case. I just want the output if the condition in property_id in matches the whole series.
This how it could be done
select
product_id from
table_name
where property_id in (2,5)
group by product_id
having count(*) = 2
All you need to change having count(*) = 2 to the number of items inside IN() , right now its 2 and if you are looking at 3 property id then it will be 3 and so on.
select distinct a.product_id
from table a, table b
where a.product_id = b.product_id
and a.property_id = 2
and b.property_id = 5
I am using user Keevas' example, but asking a different question....
select Master_Code, SUM(Jan), SUM(Feb), SUM(Mar)
from dbo.foobar
WHERE Participating_City = 'foofoo'
GROUP BY Master_Code ORDER BY Master_Code ASC
something like this:
Master_Code sum(Jan) Sum(Feb) sum(Mar) Total
1 4 5 4 13
2 5 5 5 15
How do I get Total value column?
SELECT username,SUM(value) AS SumValue FROM
table GROUP BY username ORDER BY SumValue DESC
:-)
I have this script, which find a users position taken from the number of credits.
It all works, but i have a little problem. If two users have the same credits, both of them will be on the same position.
Can I do, so if there are more users with same credits, then the system need to order by the users ID and out from that give them a position?
This is my code so far:
$sql = "SELECT COUNT(*) + 1 AS `number`
FROM `users`
WHERE `penge` >
(SELECT `penge` FROM `users`
WHERE `facebook_id` = ".$facebook_uid.")";
$query_rang = $this->db->query($sql);
So if i have this:
ID -------- Credits
1 -------- 100
2 -------- 100
3 -------- 120
Then the rank list should be like this:
Number 1 is user with ID 3
Number 2 is user with ID 1
Number 3 is user with ID 2
ORDER BY credits DESC, id ASC. This will sort by credits and break ties with the id.
UPDATE
I understand now that you want the ranking information for the user, not just to sort the users by credits and ids. This will give you the complete list of users and their rankings:
SELECT #rank:=#rank+1 AS rank, users.id, users.facebook_id FROM users, (SELECT #rank:=0) dummy ORDER BY penge DESC, id ASC
Getting the row number is the tricky bit solved by this blog post:
http://jimmod.com/blog/2008/09/displaying-row-number-rownum-in-mysql/
$sql = "SELECT COUNT(*) + 1 AS `number` FROM `users` WHERE `penge` > (SELECT `penge` FROM `users` WHERE `facebook_id` = ".$facebook_uid.") ORDER BY COUNT(*) + 1 desc, users.ID";
$query_rang = $this->db->query($sql);
Later EDIT:
I don't understand why you still have the same results....
I made a quick test. I have created a table:
Test: ID (Integer) and No (Integer)
I have inserted some values:
id no
1 1
1 1
1 1
2 1
3 1
4 1
4 1
5 1
Now, if I run:
SELECT
id, COUNT(*) + 1 AS `number`
FROM
test
GROUP BY
id
I get:
id number
1 4
2 2
3 2
4 3
5 2
But if I add ORDER BY:
SELECT
id, COUNT(*) + 1 AS `number`
FROM
test
GROUP BY
id
ORDER BY
count(*) desc, id
then I get:
id number
1 4
4 3
2 2
3 2
5 2
If I have a single field, say, project_id where I want to count the occurrences, I would do something like:
select project_id, count(project_id) as count from tbl group by project_id, order by count desc
What if I want to count the occurrences of a combination of two fields in the same table, i.e. count the number of rows where the combination of project_id and service_id are unique?
So, so I have records in my table like:
project_id service_id
1 1
1 2
1 2
1 2
1 2
1 3
1 4
1 4
1 4
I would want the result of my query to be something like:
project_id service_id count
1 1 1
1 2 4
1 3 1
1 4 3
select project_id, service_id, count(*) as count
from tbl group by project_id, service_id
order by count(*) desc
Just add service_id to your group by and select list. That should do it.
EDIT -
As per comment from #Rajah it seems that for your expected output, you need to use
order by project_id asc, service_id asc