Transform Statement from Access to DB2 - ms-access

I have the following query that I am trying to understand and convert
it to a db2 format:
TRANSFORM Sum(Cases) AS SumOfCases
SELECT Process, Sum(Cases) AS total
FROM tbl
GROUP BY Process
PIVOT tbl.STATUS;
Table has data like:
Process Status Cases
a Cancelled 14
a Closed 179
b Cancelled 20
b Closed 30
b Pending 10
How can I write that query to db2?
I tried the following query:
SELECT Process
, MAX(CASE WHEN STATUS = 'Cancelled' THEN CASES END) "Cancelled"
, MAX(CASE WHEN STATUS = 'Closed' THEN CASES END) "Closed"
, MAX(CASE WHEN STATUS = 'Pending' THEN CASES END) "Pending"
FROM tbl
GROUP BY Process;
Since I do not have MS Access hence I am not confident that if I had done the right thing in db2 or not.
Would appreciate if I could get some advice on this.

Your DB2 query works correctly in replicating Access's crosstab query except you missed the Total column. By the way any aggregate function would work for your CASE/WHEN statements: MIN(), MAX(), MEDIAN(), AVG(), even SUM():
SELECT Process
, SUM(CASES) AS "Total"
, MAX(CASE WHEN STATUS = 'Cancelled' THEN CASES END) AS "Cancelled"
, MAX(CASE WHEN STATUS = 'Closed' THEN CASES END) AS "Closed"
, MAX(CASE WHEN STATUS = 'Pending' THEN CASES END) AS "Pending"
FROM tbl
GROUP BY Process;

Related

Diffrence between sum of two products > 0

I want to select the sum of T_No where Transactions are equal to R and subtract it by T_No where Transactions are equal to D and the answer of this should greater than zero for a CustomerID which would be a input (an int input declared in a stored procedure)
((Sum(T_No) where Transactions = R - Sum(T_No) where Transactions = D ) > 0) where CoustomerID = #input
Example : for ID = 1 it would be ((20+15) - 10) > 0
I Have tried so many things but either syntax is wrong, wrong value or it does not accept, and I am literally Stuck, this was my final attempt
SELECT
(select ( select Sum(T_No) where Transactions = R) - (select Sum(T_No) where Transactions = D) as C_T )
FROM CustomerTrans WHERE C_T > 0 ;
Conditional aggregation should help:
SELECT
SUM(CASE WHEN Transaction = 'R' THEN t_no ELSE 0 END) - SUM(CASE WHEN Transaction = 'D' THEN t_no ELSE 0 END)
FROM CustomerTrans
WHERE CoustomerID = #yourCustomerIdVariable
As you're writing a sproc you can assign the result of this to a variable and then decide what to do if the result is negative. (I would personally log an error for example, rather than just hide those results). If the result is null, then there were no transactions for that customer
ps; I used Transaction because that's what your screenshot showed, and I figured a screenshot is less likely to contain a typo than code with syntax errors. Adjust if required
you where kinda close, I would sum like you, only the syntax is a bit off, you can't have aggregate fields in Where, thats why you should use having, also case when syntax is not correct.
Select
CoustomerID,
Sum(case when Transactions = 'R' then T_No else 0 end) -
Sum(case when Transactions = 'D' then T_No else 0 end) as C_T
FROM CustomerTrans
group by CoustomerID
having (Sum(case when Transactions = 'R' then T_No else 0 end) -
Sum(case when Transactions = 'D' then T_No else 0 end))>0

how to get the desired result based on some certain condition in sql using case?

I have a table which traces the users records I want to know which are the complete and process users's records based on their status
Here is the sql query
SELECT users.UserID,users.UserName,users.FirstName,users.LastName,users.Email,
CASE WHEN inword.inword_status = '3' THEN count(*) END As 'Process' ,
CASE WHEN inword.inword_status = '4' THEN count(*) END AS 'Complete'
FROM tbl_user users
INNER JOIN tbl_inword inword on users.UserID=inword.UserID
Where inword.Status=1 and users.Status=1 and
inword.CreatedDate BETWEEN '2020-10-01' and '2020-10-31' and inword.inword_status in (3)
group by users.UserID
Here is Query Output
My Expected result is
UserID Name Total Process Complete
1 Umair 1 1 0
1 Basit 20 20 0
1 Zaidi 34 32 2
Any Help would be Appreciated
You're not doing your conditional aggregation correctly, you should use something like:
COUNT(CASE WHEN inword.inword_status = '3' THEN inword.UserId END) As 'Process' ,
COUNT(CASE WHEN inword.inword_status = '4' THEN inword.UserId END) AS 'Complete'
Or you can take advantage of MySQL treating booleans as 1 or 0 in a numeric context and simplify to:
SUM(inword.inword_status = '3') As 'Process' ,
SUM(inword.inword_status = '4') AS 'Complete'

Sum on same column with two different conditions mysql

I have a table named Order with schema as
user_id, state amount
11 success 100
11 FAILED 10
11 FAILED 10
11 success 17
state can have two values (Success/Failed).
I want to fetch sum(amount) when state = "SUCCESS" - sum(amount) when state = "FAILED"
means difference total amount when success - total amount when failed.
I can solve this problem in 2 queries.
A = select id, sum(amount) when state = "SUCCESS"
B = select id, sum(amount) when state = "FAILED"
And solution will be A-B.
Is there any way I can achieve this in single sql query?
use case when
select user_id,sum(case when state = 'SUCCESS' then amount else 0 end)-sum(case when state = 'FAILED' then amount else 0 end)
from table group by user_id
Use conditional aggregation:
select id,
sum(case when state = 'SUCCESS' then amount else - amount end) as total
from t
where state in ('SUCCESS', 'FAILED')
group by id;
I assume that you want this sum per id and not overall in the table.
select sum(case when state = "SUCCESS" then amount else o end) -
sum(case when state = "FAILED" then amount else o end)
from tbl
group by userid

Grouping by months and by column with diferent values

I am having problems trying to create a query that allow me to group by months and by a column that has different values.
The following is a small representation of the table and columns I need to query.
Table name is requests and has two columns date and status. Status may have the values pending, attended, absent and canceled.
I want to get a query that looks like this
Right now i am trying a subquery on status for each possible value. It works but is a very slow query. It takes arround 48s for 8000 rows.
SELECT
MONTHNAME(date)
(SELECT count(status) FROM requests WHERE status = "pending"),
(SELECT count(status) FROM requests WHERE status = "attended"),
(SELECT count(status) FROM requests WHERE status = "absent"),
(SELECT count(status) FROM requests WHERE status = "canceled")
FROM request
GROUP BY 1;
Any recommendations on how to get the result efficiently? Thank you very much
You could use case whene on status instead of several subselect
select
MONTHNAME(date)
, sum( case when status = "pending" then 1 else 0 end) pending
, sum( case when status = "attended" then 1 else 0 end) attended
, sum( case when status = "absent" then 1 else 0 end) absent
, sum( case when status = "canceled" then 1 else 0 end) canceled
FROM request
GROUP BY MONTHNAME(date) ;

Difference between these two mysql queries

I want to know the difference between these two queries: The first query is giving me all the records and its just fine.
Select * from table1 where tender_id='$tender_id' group by supplier_name
But in the following query I have added a sum(case), but I am not getting the desired output. The first query is showing all the records, but the second query is not showing all the records. What mistake am I making?
select cs.*, tender_id,
SUM(CASE WHEN ifmain = 'Yes' THEN total_inr ELSE 0 END) AS maintotal,
SUM(CASE WHEN ifmain = 'No' THEN total_inr ELSE 0 END) AS subtotal
from table1 cs
where cs.tender_id='$tender_id'
group by cs.supplier_name
I want to know if the second query can display all the records with conditions (tender_id)? or its iterating more?
In standard SQL, a query that includes a GROUP BY clause cannot refer
to nonaggregated columns in the select list that are not named in the
GROUP BY clause.
see (for example) https://dev.mysql.com/doc/refman/5.0/en/group-by-handling.html
MySQL has a an unfortunate (and in my opinion incorrect) default behavior when using a GROUP BY clause. This query would NOT be valid in most SQL databases:
Select * from table1 where tender_id='$tender_id' group by supplier_name
and it would not be valid in MySQL either if the ONLY_FULL_GROUP_BY SQL mode has been enabled.
I strongly recommend you treat all queries using GROUP BY as needing ALL non-aggregating columns in that clause. e.g.
select
cs.supplier_name
, SUM(CASE WHEN ifmain = 'Yes' THEN total_inr ELSE 0 END) AS maintotal
, SUM(CASE WHEN ifmain = 'No' THEN total_inr ELSE 0 END) AS subtotal
from table1 cs
where cs.tender_id='$tender_id'
group by
cs.supplier_name
If you need extra columns then e.g.
select
cs.supplier_name
, tender_id
, SUM(CASE WHEN ifmain = 'Yes' THEN total_inr ELSE 0 END) AS maintotal
, SUM(CASE WHEN ifmain = 'No' THEN total_inr ELSE 0 END) AS subtotal
from table1 cs
where cs.tender_id='$tender_id'
group by
cs.supplier_name
, tender_id
and so on. Of course as you include more columns in the group by clause you may increase the number of rows produced, but that is how GROUP BY should work.