Table:
laterecords
-----------
studentid - varchar
latetime - datetime
reason - varchar
students
--------
studentid - varchar -- Primary
class - varchar
I would like to do a query to show the following:
Sample Report
Class No of Students late 1 times 2 times 3 times 4 times 5 & more
Class A 3 1 0 2 0 0
Class B 1 0 1 0 0 0
My query below can show the first column results:
SELECT count(Distinct studentid), class FROM laterecords, students
WHERE students.studenid=laterecords.studentid AND
GROUP BY class
I can only think of getting the results for each column and store them into php arrays. Then echo them to table in HTML.
Is there any better SQL way to do the above? How to do up the mysql query ?
Try this:
SELECT
a.class,
COUNT(b.studentid) AS 'No of Students late',
SUM(b.onetime) AS '1 times',
SUM(b.twotime) AS '2 times',
SUM(b.threetime) AS '3 times',
SUM(b.fourtime) AS '4 times',
SUM(b.fiveormore) AS '5 & more'
FROM
students a
LEFT JOIN
(
SELECT
aa.studentid,
IF(COUNT(*) = 1, 1, 0) AS onetime,
IF(COUNT(*) = 2, 1, 0) AS twotime,
IF(COUNT(*) = 3, 1, 0) AS threetime,
IF(COUNT(*) = 4, 1, 0) AS fourtime,
IF(COUNT(*) >= 5, 1, 0) AS fiveormore
FROM
students aa
INNER JOIN
laterecords bb ON aa.studentid = bb.studentid
GROUP BY
aa.studentid
) b ON a.studentid = b.studentid
GROUP BY
a.class
How about :
SELECT numlates, `class`, count(numlates)
FROM
(SELECT count(laterecords.studentid) AS numlates, `class`, laterecords.studentid
FROM laterecords,
students
WHERE students.studentid=laterecords.studentid
GROUP BY laterecords.studentid, `class`) aliastbl
GROUP BY `class`, numlates
Related
I am trying to get the number of 'critics' and 'promoters' from average of ratings from a joined table on a specific group of questions
SELECT category
, SUM( IF( round(avg(items.value) ) <= 6, 1, 0) ) AS critics
, SUM( IF( round(avg(items.value) ) >= 9, 1, 0) ) AS promoters
FROM reviews
INNER JOIN items
ON reviews.id = items.review_id
AND items.question_id in (1, 2, 4)
GROUP BY category
However I get the error:
General error: 1111 Invalid use of group function
I think you should try with using having with it, something like below:
SELECT
category,
COUNT(items.id) AS critics
FROM reviews
INNER JOIN items ON reviews.id = items.review_id AND
items.question_id IN (1, 2, 4)
GROUP BY category
HAVING ROUND(AVG(items.value)) <= 6
First retrieve category wise rounded average value and then apply condition either it is critics and promoters.
-- MySQL
SELECT t.category
, CASE WHEN t.avg_value <= 6
THEN 1
ELSE 0
END critics
, CASE WHEN t.avg_value >= 9
THEN 1
ELSE 0
END promoters
FROM (SELECT category
, ROUND(AVG(items.value)) avg_value
FROM reviews
INNER JOIN items
ON reviews.id = items.review_id
AND items.question_id IN (1, 2, 4)
GROUP BY category) t
Please check this url for finding out pseudocode https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=2679b2be50c3059c73ab9754c612179c
First retrieve category and review_id wise rounded average value and then apply condition either it is critics and promoters.
SELECT t.category
, SUM(CASE WHEN t.avg_value <= 6
THEN 1
ELSE 0
END) critics
, SUM(CASE WHEN t.avg_value >= 9
THEN 1
ELSE 0
END) promoters
FROM (SELECT category
, items.review_id
, ROUND(AVG(items.value)) avg_value
FROM reviews
INNER JOIN items
ON reviews.id = items.review_id
AND items.question_id IN (1, 2, 4)
GROUP BY category
, items.review_id) t
GROUP BY t.category
Issues in getting the right frequency for the cross tabulated data. My expected output is something like this:
I tried replacing the COUNT statement with SUM statement
SUM(IF(product.product_id = 1, line_item.quantity, 0)) AS Soda,
SUM(IF(product.product_id = 2, line_item.quantity, 0)) AS Liquor,
SUM(IF(product.product_id = 3, line_item.quantity, 0)) AS Lemon,
SUM(IF(product.product_id = 4, line_item.quantity, 0)) AS Mango,
SUM(IF(product.product_id = 5, line_item.quantity, 0)) AS Inhaler,
SUM(1) AS Count
FROM line_item
JOIN product USING (product_id)
JOIN ( SELECT 0 lo, 500 hi UNION
SELECT 501 , 1000 UNION
SELECT 1001 , 1500 UNION
SELECT 1501 , 2000 UNION
SELECT 2001 , 2500 ) ranges ON (product.price * line_item.quantity) BETWEEN ranges.lo AND ranges.hi
GROUP BY ranges.lo, ranges.hi```
It is getting closer because it is distributing already the values in its ranges just that the values are not correct. I am expecting to see something like this:
[Expected Result][1]
[1]: https://i.stack.imgur.com/YuB92.png
After reviewing my code here is the answer:
SUM(product.product_id = 1) AS Soda,
SUM(product.product_id = 2) AS Liquor,
SUM(product.product_id = 3) AS Lemon,
SUM(product.product_id = 4) AS Mango,
SUM(product.product_id = 5) AS Inhaler,
SUM(1) AS Count
FROM line_item
JOIN product USING (product_id)
JOIN ( SELECT 0 lo, 500 hi UNION
SELECT 501 , 1000 UNION
SELECT 1001 , 1500 UNION
SELECT 1501 , 2000 UNION
SELECT 2001 , 2500 ) ranges ON product.price * line_item.quantity BETWEEN ranges.lo AND ranges.hi
GROUP BY ranges.lo, ranges.hi
I am new to sql language and recently snowflake. I have a table that contains all checkin dates for all users for a business
user_id | checkin_date
001 03-06-2018
001 07-07-2018
001 08-01-2018
002 03-19-2018
002 03-27-2018
002 07-11-2018
Now I want to do a query such that I can look back from a query_date to see how many times each user checked in between query_date - 7 and query_date, qyery_date - 90 and query date ... the following snowflake query does the job properly for query_date='2018-08-01'.
with user_checkin_history_sum as (
select
user_id,
sum(iff(datediff(DAY, uc.checkin_date, '2018-08-01') <= 7, 1, 0)) as visits_past_7_days,
sum(iff(datediff(DAY, uc.checkin_date, '2018-08-01') <= 90, 1, 0)) as visits_past_90_days,
from user_checkin as uc
where uc.checkin_date < '2018-08-01'
group by user_id
order by user_id
)
This gives me result
user_id | visits_past_7_days | visits_past_90_days
001 0 2
002 0 1
My question is, if I have more than one day as the query_date, i.e., I have a list of checkin_date, for each checkin_date in the list, I do the query as above and append all them together. Basically, it is a loop over + table append, but I do not find an answer how to do this in sql language. Essentially, what I want to do is like the following
with user_checkin_history_sum as (
select
user_id,
sum(iff(datediff(DAY, uc.checkin_date, query_date) <= 7, 1, 0)) as visits_past_7_days,
sum(iff(datediff(DAY, uc.checkin_date, query_date) <= 90, 1, 0)) as visits_past_90_days,
from user_checkin as uc
where uc.checkin_date < query_date and
LOOP OVER
query_date in ('2018-08-01', '2018-06-01')
group by user_id
order by user_id
)
And hopefully it gives this result
user_id | query_date | visits_past_7_days | visits_past_90_days
001 '08-01-2018' 0 2
002 '08-01-2018' 0 1
001 '06-01-2018' 0 1
002 '06-01-2018' 0 2
You should be able to cross join a table containing all the dates you want to examine:
WITH dates AS (
SELECT '2018-06-01' AS query_date UNION ALL
SELECT '2018-08-01' UNION ALL
... -- maybe other dates as well
),
user_checkin_history_sum AS (
SELECT
uc.user_id,
d.query_date,
SUM(IFF(DATEDIFF(DAY, uc.checkin_date, d.query_date) <= 7, 1, 0)) AS visits_past_7_days,
SUM(IFF(DATEDIFF(DAY, uc.checkin_date, d.query_date) <= 90, 1, 0)) AS visits_past_90_days
FROM dates d
CROSS JOIN user_checkin AS uc
WHERE uc.checkin_date < '2018-08-01'
GROUP BY d.query_date, uc.user_id
ORDER BY d.query_date, uc.user_id
)
I want to be able to select the amount of times the data in columns Somedata_A and Somedata_B has changed from the from the previous row within its column. I've tried using DISTINCT and it works to some degree. {1,2,3,2,1,1} will show 3 when I want it to show 4 course there's 5 different values in sequence.
Example:
A,B,C,D,E,F
{1,2,3,2,1,1}
A compare to B gives a difference, B compare to C gives a difference . . . E compare to F gives not difference. All in all it gives 4 differences within a set of 6 values.
I have gotten DISTINCT to work but it does not really do the trick for me. And to add more to the question I'm really not interested it the whole range, lets say just the 2 last days/entries per Title.
Second I'm concern about performance issues. I tried the query below on a real set of data and it got interrupted probably due to timeout.
SQL Fiddle
MySQL 5.5.32 Schema Setup:
CREATE TABLE testdata(
Title varchar(10),
Date varchar(10),
Somedata_A int(5),
Somedata_B int(5));
INSERT INTO testdata (Title, Date, Somedata_A, Somedata_B) VALUES
("Alpha", '123', 1, 2),
("Alpha", '234', 2, 2),
("Alpha", '345', 1, 2),
("Alpha", '349', 1, 2),
("Alpha", '456', 1, 2),
("Omega", '123', 1, 1),
("Omega", '234', 2, 2),
("Omega", '345', 3, 3),
("Omega", '349', 4, 3),
("Omega", '456', 5, 4),
("Delta", '123', 1, 1),
("Delta", '234', 2, 2),
("Delta", '345', 1, 3),
("Delta", '349', 2, 3),
("Delta", '456', 1, 4);
Query 1:
SELECT t.Title, (SELECT COUNT(DISTINCT Somedata_A) FROM testdata AS tt WHERE t.Title = tt.Title) AS A,
(SELECT COUNT(DISTINCT Somedata_B) FROM testdata AS tt WHERE t.Title = tt.Title) AS B
FROM testdata AS t
GROUP BY t.Title
Results:
| TITLE | A | B |
|-------|---|---|
| Alpha | 2 | 1 |
| Delta | 2 | 4 |
| Omega | 5 | 4 |
Something like this may work: it uses a variable for row number, joins on an offset of 1 and then counts differences for A and B.
http://sqlfiddle.com/#!2/3bbc8/9/2
set #i = 0;
set #j = 0;
Select
A.Title aTitle,
sum(Case when A.SomeData_A <> B.SomeData_A then 1 else 0 end) AVar,
sum(Case when A.SomeData_B <> B.SomeData_B then 1 else 0 end) BVar
from
(SELECT Title, #i:=#i+1 as ROWID, SomeData_A, SomeData_B
FROM testdata
ORDER BY Title, date desc) as A
INNER JOIN
(SELECT Title, #j:=#j+1 as ROWID, SomeData_A, SomeData_B
FROM testdata
ORDER BY Title, date desc) as B
ON A.RowID= B.RowID + 1
AND A.Title=B.Title
Group by A.Title
This works (see here) (FYI: Your results in the question do not match your data - for instance, for Alpha, ColumnA: it never changes from 1. The answer should be 0)
Hopefully you can adapt this Statement to your actual data model
SELECT t1.title, SUM(t1.Somedata_A<>t2.Somedata_a) as SomeData_A
,SUM(t1.Somedata_b<>t2.Somedata_b) as SomeData_B
FROM testdata AS t1
JOIN testdata AS t2
ON t1.title = t2.title
AND t2.date = DATE_ADD(t1.date, INTERVAL 1 DAY)
GROUP BY t1.title
ORDER BY t1.title;
Given a model like this
ProductFacets contains the following data:
ProductId, FacetTypeId
1, 1
1, 2
2, 1
2, 3
3, 4
3, 5
4, 1
4, 2
I'd like to be able to select all Products which have a FacetTypeId of 1 AND 2.
The result set should contain ProductIds 1 and 4
This will return rows for products that have only facet types 1 and 2, and only those facets.
SELECT ProductId,
COUNT(*) AS FacetCountByProduct,
SUM(CASE WHEN FacetTypeId in (1, 2) THEN 1 ELSE 0 END) AS FacetCountSelectedFacets
FROM ProductFacets
GROUP BY ProductId
HAVING COUNT(*) = 2
and SUM(CASE WHEN FacetTypeId in (1, 2) THEN 1 ELSE 0 END) = 2
;
SELECT * FROM Product PROD WHERE PROD.ProductId IN(
SELECT P.ProductId pId FROM ProductFacets AS P
WHERE P.FacetTypeId = 1
AND EXISTS
(
SELECT *
FROM ProductFacets AS P1
WHERE P1.FacetTypeid = 2
AND P1.ProductId = pId
)
AND NOT EXISTS
(
SELECT *
FROM ProductFacets AS P2
WHERE P2.FacetTypeid NOT IN (1,2)
AND P2.ProductId = pId
)
)
There must be a better way to solve this, but it's the only one i can come up with
Just thought of a way to do this:
select distinct ProductId from ProductFacets
where ProductId in (select ProductId from ProductFacets where FacetTypeId = 1)
and ProductId in (select ProductId from ProductFacets where FacetTypeId = 2)