How to group sums by weekday in MySQL? - sql

I have a table like this:
id | timestamp | type
-----------------------
1 2010-11-20 A
2 2010-11-20 A
3 2010-11-20 B
4 2010-11-21 A
5 2010-11-21 C
6 2010-11-27 B
and I need to count the rows for each type, grouped by weekday; like this:
weekday | A | B | C
--------------------------
5 2 2 0 -- the B column equals 2 because nov 20 and nov 27 are saturday
6 1 0 1
What would be the simplest solution for this?
I don't mind using views, variables, subqueries, etc.


Use:
SELECT WEEKDAY(t.timestamp) AS weekday,
SUM(CASE WHEN t.type = 'A' THEN 1 ELSE 0 END) AS a,
SUM(CASE WHEN t.type = 'B' THEN 1 ELSE 0 END) AS b,
SUM(CASE WHEN t.type = 'C' THEN 1 ELSE 0 END) AS c
FROM YOUR_TABLE t
GROUP BY WEEKDAY(t.timestamp)

Related

Slicing table data based on days

Having the following data table:
col1
days
A
2
B
3
C
1
C
5
D
3
A
3
B
7
A
4
I want to transform it into:
col1
<=2days
<=5days
<=7days
A
1
2
0
B
0
1
1
C
1
1
0
D
0
1
0
I used the below query to achieve this:
select col1,
CASE WHEN days <=2 then count(days) as "<=2days",
CASE WHEN days > 2 and days <=5 then count(days) as "<=5days",
CASE WHEN days > 5 and days <=7 then count(days) as "<=7days"
from tableA group by col1,days
But it returns a result like the following:
col1
<=2days
<=5days
<=7days
A
1
0
0
A
0
2
0
B
0
1
0
B
0
0
1
C
0
1
0
C
1
0
0
D
0
1
0
Can someone please help here?

You could use conditional aggregation as the following:
SELECT col1,
COUNT(CASE WHEN days<=2 THEN 1 END) AS '<=2days',
COUNT(CASE WHEN days<=5 and days>2 THEN 1 END) AS '<=5days',
COUNT(CASE WHEN days<=7 and days>5 THEN 1 END) AS '<=7days'
FROM tableA
GROUP BY col1
ORDER BY col1
See a demo on MySQL.

SQL query sum of total corresponding rows

I have two tables as below. Caseid from first table is referenced in second table along with accidents. What I am trying to get total different accidents for a case type. Below two tables I documented sample data and expected result.
Table case:
caseId CaseType
1 AB
2 AB
3 AB
4 CD
5 CD
6 DE
Table CaseAccidents:
AccidentId caseID AccidentRating
1 1 High
2 1 High
3 1 Medium
4 1 LOW
5 2 High
6 2 Medium
7 2 LOW
8 5 High
9 5 High
10 5 Medium
11 5 LOW
Result should look like:
CaseType TotalHIghrating TotalMediumRating TotalLOWRating
AB 3 2 2
CD 2 1 1
DE 0 0 0

To get the sum of every rating, you can Use a SUM(CASE WHEN) clause, adding 1 by every record that match the rating.
In your question, you have pointed out that you want to see all distinct CaseType, you can get it by using a RIGHT JOIN, this will include all records of case table.
select case.CaseType,
sum(case when caseAccidents.AccidentRating = 'High' then 1 else 0 end) as TotalHighRating,
sum(case when caseAccidents.AccidentRating = 'Medium' then 1 else 0 end) as TotalMediumRating,
sum(case when caseAccidents.AccidentRating = 'LOW' then 1 else 0 end) as TotalLowRating
from caseAccidents
right join case on case.caseId = caseAccidents.caseID
group by case.CaseType;
+----------+-----------------+-------------------+----------------+
| CaseType | TotalHighRating | TotalMediumRating | TotalLowRating |
+----------+-----------------+-------------------+----------------+
| AB | 3 | 2 | 2 |
+----------+-----------------+-------------------+----------------+
| CD | 2 | 1 | 1 |
+----------+-----------------+-------------------+----------------+
| DE | 0 | 0 | 0 |
+----------+-----------------+-------------------+----------------+
Check it: http://rextester.com/MCGJA9193

Have you use case in a select clause before?
select C.CaseType,
sum(case when CA.AccidentRating = 'High' then 1 else 0 end)
from Case C join CaseAccidents CA on C.CaseId = CA.CaseId
group by C.CaseType

Please see this. Sample query of the table and also that result
create table #case(caseid int,casetype varchar(5))
insert into #case (caseid,casetype)
select 1,'AB' union all
select 2,'AB' union all
select 3,'AB' union all
select 4,'CD' union all
select 5,'CD' union all
select 6,'DE'
create table #CaseAccidents(AccidentId int, CaseId int,AccidentRating varchar(10))
insert into #CaseAccidents(AccidentId, CaseId, AccidentRating)
select 1,1,'High' union all
select 2,1,'High' union all
select 3,1,'Medium' union all
select 4,1,'Low' union all
select 5,2,'High' union all
select 6,2,'Medium' union all
select 7,2,'Low' union all
select 8,5,'High' union all
select 9,5,'High' union all
select 10,5,'Medium' union all
select 11,5,'Low'
My script
select c.casetype,
sum(case when ca.AccidentRating='High' then 1 else 0 end) as TotalHighRating,
sum(case when ca.AccidentRating='Medium' then 1 else 0 end) as TotalMediumRating,
sum(case when ca.AccidentRating='Low' then 1 else 0 end) as TotalLowRating
from #case c
Left join #CaseAccidents ca
on c.Caseid=ca.Caseid
group by c.casetype
Hope This could help!

Another approach using Pivot operator
SELECT casetype,
[High],
[Medium],
[Low]
FROM (SELECT c.casetype,
AccidentRating
FROM case c
LEFT JOIN CaseAccidents ca
ON ca.CaseId = c.caseid)a
PIVOT (Count(AccidentRating)
FOR AccidentRating IN ([High],
[Medium],
[Low]) ) p

Try This code once.
select casetype,
sum(case when ca.AccidentRating='High' then 1 else 0 end ) as TotalHIghrating,
sum(case when ca.AccidentRating='Medium' then 1 else 0 end ) as TotalMediumRating ,
sum(case when ca.AccidentRating='Low' then 1 else 0 end ) as TotalLOWRating
from #case c
left join #CaseAccidents ca on c.caseid=ca.CaseId
group by casetype

SQL Aggregate on Two tables

Table A has millions of records from 2014, Using Oracle
ID Sales_Amount Sales_Date
1 10 20/11/2014
1 10 22/11/2014
1 10 22/12/2014
1 10 22/01/2015
1 10 22/02/2015
1 10 22/03/2015
1 10 22/04/2015
1 10 22/05/2015
1 10 22/06/2015
1 10 22/07/2015
1 10 22/08/2015
1 10 22/09/2015
1 10 22/10/2015
1 10 22/11/2015
Table B
ID ID_Date
1 22/11/2014
2 01/12/2014
I want sum of totals for 6 months as well as 1 year for ID 1 taking starting
date from Table B as 22/11/2014
Output Sales_Amount_6Months Sales_Amount_6Months
1 70 130
Shall I use add_months in this case?

Yes, you can use ADD_MONTHS() and conditional aggregation :
SELECT b.id,
SUM(CASE WHEN a.sales_date between b.id_date AND ADD_MONTHS(b.id_date,6) THEN a.sales_amount ELSE 0 END) as sales_6_month,
SUM(CASE WHEN a.sales_date between b.id_date AND ADD_MONTHS(b.id_date,12) THEN a.sales_amount ELSE 0 END) as sales_12_month
FROM TableB b
JOIN TableA a
ON(b.id = a.id)
GROUP BY b.id

SQL check if column contains specific values

I have a table like this:
id | Values
------------------
1 | a
1 | b
1 | c
1 | d
1 | e
2 | a
2 | a
2 | c
2 | c
2 | e
3 | a
3 | c
3 | b
3 | d
Now I want to know which id contains at least one of a, one of b and one of c.
This is the result I want:
id
--------
1
3

One method is aggregation with having:
select id
from t
where values in ('a', 'b', 'c')
group by id
having count(distinct values) = 3;
If you wanted more flexibility with the counts of each value:
having sum(case when values = 'a' then 1 else 0 end) >= 1 and
sum(case when values = 'b' then 1 else 0 end) >= 1 and
sum(case when values = 'c' then 1 else 0 end) >= 1

You can use grouping:
SELECT id
FROM your_table
GROUP BY id
HAVING SUM(CASE WHEN value = 'a' THEN 1 ELSE 0 END) >= 1
AND SUM(CASE WHEN value = 'b' THEN 1 ELSE 0 END) = 1
AND SUM(CASE WHEN value = 'c' THEN 1 ELSE 0 END) = 1;
or using COUNT:
SELECT id
FROM your_table
GROUP BY id
HAVING COUNT(CASE WHEN value = 'a' THEN 1 END) >= 1
AND COUNT(CASE WHEN value = 'b' THEN 1 END) = 1
AND COUNT(CASE WHEN value = 'c' THEN 1 END) = 1;

How can we count sub query use group by without pivot?

I need to create query that has below result.
I add my table for example for better understanding.
QTable:
QID Name
-------
1 x
1 y
2 z
FTable:
QID FID
-------
1 1
1 2
2 3
Inner join with :
FID Type
-------
1 1
1 2
1 3
1 4
2 2
2 3
2 3
3 1
3 3
3 3
I need to result like this:
result:
QID FID-Count Type(1)-count Type(2)-count Type(3)-count Type(4)-count
-----------------------------------------------------------------
1 2 1 2 3 1
2 1 1 0 2 0
Thank u for help.

Ususally you can emulate a pivot with GROUP BY and SUM+CASE:
SELECT
T1.QID,
COUNT(DISTINCT T1.FID) as FIDCOUNT,
SUM(CASE WHEN Type=1 THEN 1 ELSE 0 END) as Type1Cnt,
SUM(CASE WHEN Type=2 THEN 1 ELSE 0 END) as Type2Cnt,
SUM(CASE WHEN Type=3 THEN 1 ELSE 0 END) as Type3Cnt,
SUM(CASE WHEN Type=4 THEN 1 ELSE 0 END) as Type4Cnt
FROM QFTable as T1
JOIN T2 ON
T1.FID=T2.FID
GROUP BY T1.QID
ORDER BY QID
SQLFiddle demo