I am having an issue creating most efficient query for multiple distinct counts of a column with different where clauses. My MYSQL table looks like this:
id client_id result timestamp
---------------------------------------------------
1 1234566 escalated 2014-01-02 00:00:00
2 1233344 approved 2014-02-03 00:00:00
3 1234566 escalated 2014-01-02 01:00:00
What I am trying to achieve is to build the following data in the return:
Total number of unique client IDs processed from the beginning of time.
Total number of unique client IDs processed escalated from the beginning of time.
Total number of unique client IDs processed approved from the beginning of time.
Count of unique client IDs approved within specified timeframe using between statement on timestamp.
Count of unique client IDs escalated within specified timeframe using between statement on timestamp.
I have thought about running multiple selects, but I think it would be a waste of resources, and possibly if this could be done with a single query it would the best way to handle it, unfortunately my experience is lacking in this area. What I would like would the return to simple contain an alias and the count.
Any help would be appreciated.
You want conditional aggregation, something like:
select count(distinct ClientId) as NumClients,
count(distinct case when result = 'Approved' then ClientId end) as NumApproved,
count(distinct case when result = 'Escalated' then ClientId end) as NumEscalated,
count(distinct case when result = 'Approved' and timestamp between #Time1 and #Time2
then ClientId end) as NumApproved,
count(distinct case when result = 'Escalated' and timestamp between #Time1 and #Time2
then ClientId end) as NumEscalated,
from table t;
Related
Have a fact table joined with dimension tables to pull out specific information.
I want to pull out id's where the status = running and they must have the running status between several dates.
If between the dates specified, the status changes to other than "running" that campaign is not counted for in the result.
I have an idea of how to approach it, but i don't think my logic and syntax is exactly correct. As I think the query below would pull data for 12345 which is not intended.
iddate
id
status
06-09
12345
running
06-10
12345
running
06-11
12345
ended
06-09
98765
running
06-10
98765
running
06-11
98765
running
The result expected should only show information for id 98765
Current SQL
SELECT
*
From....
Where status='running'
AND iddate BETWEEN DATE('2022-06-09') AND DATE('2022-06-11')
Group by 1,2,3
I believe I am likely missing a "NOT" condition somewhere to further filter out the dates.
Or the other thought is that id must have running between those dates, however, I am not sure how to apply that logic and its syntax. Any help would be appreciated.
you could do a case statement to compare the running count to the total count.
select id,
count('dracula') cnt,
sum(case when status = 'running' then 1 else 0 end) cnt2
from mytable
where iddate BETWEEN DATE('2022-06-09') AND DATE('2022-06-11')
group by id
having cnt = cnt2
here is the fiddle.
https://www.db-fiddle.com/f/fmFcwnGXyovYezBSCQ4aac/0
Instead of selecting those that had status = 'running', you could filter out those that don't have status = 'running', in the specified time frame.
WITH cte AS (
SELECT *
FROM tab
WHERE iddate BETWEEN DATE('2022-06-09') AND DATE('2022-06-11')
)
SELECT DISTINCT id
FROM cte
WHERE id NOT IN (SELECT id FROM cte WHERE NOT status = 'running')
Check the demo here.
I have a data set like this:
User Date Status
Eric 1/1/2015 4
Eric 2/1/2015 2
Eric 3/1/2015 4
Mike 1/1/2015 4
Mike 2/1/2015 4
Mike 3/1/2015 2
I'm trying to write a query in which I will retrieve users whose MOST RECENT transaction status is a 4. If it's not a 4 I don't want to see that user in the results. This dataset could have 2 potential results, one for Eric and one for Mike. However, Mike's most recent transaction was not a 4, therefore:
The return result would be:
User Date Status
Eric 3/1/2015 4
As this record is the only record for Eric that has a 4 as his latest transaction date.
Here's what I've tried so far:
SELECT
user, MAX(date) as dates, status
FROM
orders
GROUP BY
status,
user
This would get me to a unqiue record for every user for every status type. This would be a subquery, and the parent query would look like:
SELECT
user, dates, status
WHERE
status = 4
GROUP BY
user
However, this is clearly flawed as I don't want status = 4 records IF their most recent record is not a 4. I only want status = 4 when the latest date is a 4. Any thoughts?
SELECT user, date
, actualOrders.status
FROM (
SELECT user, MAX(date) as date
FROM orders
GROUP BY user) AS lastOrderDates
INNER JOIN orders AS actualOrders USING (user, date)
WHERE actualOrders.status = 4
;
-- Since USING is being used, there is not a need to specify source of the
-- user and date fields in the SELECT clause; however, if an ON clause was
-- used instead, either table could be used as the source of those fields.
Also, you may want to rethink the field names used if it is not too late and user and date are both found here.
SELECT user, date, status FROM
(
SELECT user, MAX(date) as date, status FROM orders GROUP BY user
)
WHERE status = 4
The easiest way is to include your order table a second time in a subquery in your from clause in order to retrieve the last date for each user. Then you can add a where clause to match the most recent date per user, and finally filter on the status.
select orders.*
from orders,
(
select ord_user, max(ord_date) ord_date
from orders
group by ord_user
) latestdate
where orders.ord_status = 4
and orders.ord_user = latestdate.ord_user
and orders.ord_date = latestdate.ord_date
Another option is to use the over partition clause:
Oracle SQL query: Retrieve latest values per group based on time
Regards,
I have a membership list with over 1.2M members. People commonly subscribe, unsubscribe, and re-subscribe to the list. Often, I find myself needing to know which users were subscribed at a particular moment in time. I have a table called subscription_history, with this structure:
-----------------------------------------------------------------------
| id | native key |
-----------------------------------------------------------------------
| user_id | foreign key that joins the user table |
-----------------------------------------------------------------------
| change_code | 1 or 2 for subscriptions, 4-7 for unsubscriptions |
-----------------------------------------------------------------------
| created_at | date-time stamp when the change was made |
-----------------------------------------------------------------------
Right now, if I want to know who was subscribed at a particular date in the past (March 31, 2012 in this example), I run this query:
SELECT user_id
FROM
(SELECT
user_id
, MAX(created_at) AS last_change_date
, change_code
FROM subscriptionhistory
WHERE DATE(created_at) <= '2012-03-31'
GROUP BY user_id
) AS last
WHERE change_code IN (1,2)
This finds each user's last subscription action before or on the target date, then returns the user if that action was a subscription. We then use that list of users to run various other queries, such as the average lifetime sales. This system works well, but only for one date at a time. If I wanted to know the average subscriber's lifetime sales for every month of the year, I would have to run this query 12 times, manually incrementing the date in the WHERE statement each time.
Now I want to create a version of this that can I can use for more than a single date... so that it could give me all users subscribed in January, then February, etc., and I could run average lifetime sales for subscribers in each month. I can't just do a GROUP BY for this, since someone who was a subscriber in March might have unsubscribed in April and re-subscribed in June. I suppose I could 12 UNION queries ... but was hoping for something a little more elegant!
A few limiting parameters: I only have read-only access to the database; I cannot change anything about the table structure or make temporary tables. I have to do this only in MySQL - because of the way our CRM works, I can't use Python or PHP to manipulate results. Any help would be greatly appreciated! Please let me know if I am not explaining this well. Thanks!
SELECT user_id, group_concat(date_format(created_at, '%Y-%m')) as ActiveMonth from
(SELECT user_id, created_at, change_code from Subscriptions WHERE
change_code in (1,2) order by 1,2,3) b
group by user_id
order by user_id, ActiveMonth desc
You can take the group_concat out and the group by and it should give you a row and active month for every user_id.
I created a SQLFiddle and changed the table name to subscriptions for ease of use.
http://sqlfiddle.com/#!2/6b2f2/14
I think it will be easiest to start with the table I have and the result I am aiming for.
Name | Date
A | 03/01/2012
A | 03/01/2012
B | 02/01/2012
A | 02/01/2012
B | 02/01/2012
A | 02/01/2012
B | 01/01/2012
B | 01/01/2012
A | 01/01/2012
I want the result of my query to be:
Name | 01/01/2012 | 02/01/2012 | 03/01/2012
A | 1 | 2 | 2
B | 2 | 2 | 0
So basically I want to count the number of rows that have the same date, but for each individual name. So a simple group by of dates won't do because it would merge the names together. And then I want to output a table that shows the counts for each individual date using php.
I've seen answers suggest something like this:
SELECT
NAME,
SUM(CASE WHEN GRADE = 1 THEN 1 ELSE 0 END) AS GRADE1,
SUM(CASE WHEN GRADE = 2 THEN 1 ELSE 0 END) AS GRADE2,
SUM(CASE WHEN GRADE = 3 THEN 1 ELSE 0 END) AS GRADE3
FROM Rodzaj
GROUP BY NAME
so I imagine there would be a way for me to tweak that but I was wondering if there is another way, or is that the most efficient?
I was perhaps thinking if the while loop were to output just one specific name and date each time along with the count, so the first result would be A,01/01/2012,1 then the next A,02/01/2012,2 - A,03/01/2012,3 - B,01/01/2012,2 etc. then perhaps that would be doable through a different technique but not sure if something like that is possible and if it would be efficient.
So I'm basically looking to see if anyone has any ideas that are a bit outside the box for this and how they would compare.
I hope I explained everything well enough and thanks in advance for any help.
You have to include two columns in your GROUP BY:
SELECT name, COUNT(*) AS count
FROM your_table
GROUP BY name, date
This will get the counts of each name -> date combination in row-format. Since you also wanted to include a 0 count if the name didn't have any rows on a certain date, you can use:
SELECT a.name,
b.date,
COUNT(c.name) AS date_count
FROM (SELECT DISTINCT name FROM your_table) a
CROSS JOIN (SELECT DISTINCT date FROM your_table) b
LEFT JOIN your_table c ON a.name = c.name AND
b.date = c.date
GROUP BY a.name,
b.date
SQLFiddle Demo
You're asking for a "pivot". Basically, it is what it is. The real problem with a pivot is that the column names must adapt to the data, which is impossible to do with SQL alone.
Here's how you do it:
SELECT
Name,
SUM(`Date` = '01/01/2012') AS `01/01/2012`,
SUM(`Date` = '02/01/2012') AS `02/01/2012`,
SUM(`Date` = '03/01/2012') AS `03/01/2012`
FROM mytable
GROUP BY Name
Note the cool way you can SUM() a condition in mysql, becasue in mysql true is 1 and false is 0, so summing a condition is equivalent to counting the number of times it's true.
It is not more efficient to use an inner group by first.
Just in case anyone is interested in what was the best method:
Zane's second suggestion was the slowest, I loaded in a third of the data I did for the other two and it took quite a while. Perhaps on smaller tables it would be more efficient, and although I am not working with a huge table roughly 28,000 rows was enough to create significant lag, with the between clause dropping the result to about 4000 rows.
Bohemian's answer gave me the least amount to code, I threw in a loop to create all the case statements and it worked with relative ease. The benefit of this method was the simplicity, besides creating the loop for the cases, the results come in without the need for any php tricks, just simple foreach to get all the columns. Recommended for those not confident with php.
However, I found Zane's first suggestion the quickest performing and despite the need for extra php coding it seems I will be sticking with this method. The disadvantage of this method is that it only gives the dates that actually have data, so creating a table with all the dates becomes a bit more complicated. What I did was create a variable that keeps track of what date it is supposed to be compared to the table column which is reset on each table row, when the result of the query is equal to that date it echoes the value otherwise it does a while loop echoing table cells with 0 until the dates do match. It also had to do a check to see if the 'Name' value is still the same and if not it would switch to the next row after filling in any missing cells with 0 to the end of that row. If anyone is interested in seeing the code you can message me.
Results of the two methods over 3 months of data (a column for each day so roughly 90 case statements) ~ 12,000 rows out of 28,000:Bohemian's Pivot - ~0.158s (highest seen ~0.36s)Zane's Double Group by - ~0.086s (highest seen ~0.15s)
Evening folks,
I have a complex MySQL COUNT query I am trying to perform and am looking for the best way to do it.
In our system, we have References. Each Reference can have many (or no) Income Sources, each of which can be validated or not (status). We have a Reference table and an Income table - each row in the Income table points back to Reference with reference_id
On our 'Awaiting' page (the screen that shows each Income that is yet to be validated), we show it grouped by Reference. So you may, for example, see Mr John Smith has 3 Income Sources.
We want it to show something like "2 of 3 Validated" beside each row
My problem is writing the query that figures this out!
What I have been trying to do is this, using a combination of PHP and MySQL to bridge the gap where SQL (or my knowledge) falls short:
First, select a COUNT of the number of incomes associated with each reference:
SELECT `reference_id`, COUNT(status) AS status_count
FROM (`income`)
WHERE `income`.`status` = 0
GROUP BY `reference_id`
Next, having used PHP to generate a WHERE IN clause, proceed to COUNT the number of confirmed references from these:
SELECT `reference_id`, COUNT(status) AS status_count
FROM (`income`)
WHERE `reference_id` IN ('8469', '78969', '126613', ..... etc
AND status = 1
GROUP BY `reference_id`
However this doesn't work. It returns 0 rows.
Any way to achieve what I'm after?
Thanks!
In MySQL, you can SUM() on a boolean expression to get a count of the rows where that expression is true. You can do this because MySQL treats true as the integer 1 and false as the integer 0.
SELECT `reference_id`,
SUM(`status` = 1) AS `validated_count`,
COUNT(*) AS `total_count`
FROM `income`
GROUP BY `reference_id`