Query for count and distinct - sql

Question

I should make a report in T-SQL from several table.
I can join all the table needed but after I don't know excatly how to get my information.
Explanation :
I've got the following table :
Tbl_User (UserId, Username)
Tbl_Customer (CustomeriD, CustomerName)
Tbl_DocA (DocId, CustomerID, DateCreate, DateAdd, UseriD)
Tbl_DocB (DocId, CustomerID, DateCreate, DateAdd, UseriD)
Tbl_DocC (DocId, CustomerID, DateCreate, DateAdd, UseriD)
I am trying to get a report like this :
After I can get this, the idea is to have a filter with the date in SQL reporting.

Answer 1

You can union all the document tables together and join users and customers on it.
SELECT Customer.CustomerID
,Customer.CustomerName
,COUNT(CASE WHEN DocType = 'A' THEN 1 END) AS doc_a_total
,COUNT(CASE WHEN DocType = 'B' THEN 1 END) AS doc_b_total
,COUNT(CASE WHEN DocType = 'C' THEN 1 END) AS doc_c_total
,COUNT(CASE WHEN DocType = 'A' AND user.username ='azerty' THEN 1 END) AS doc_a_made_by_azerty
,COUNT(CASE WHEN DocType = 'B' AND user.username ='azerty' THEN 1 END) AS doc_b_made_by_azerty
,COUNT(CASE WHEN DocType = 'C' AND user.username ='azerty' THEN 1 END) AS doc_c_made_by_azerty
FROM (
(SELECT 'A' AS DocType, * FROM Tbl_DocA)
UNION ALL
(SELECT 'B' AS DocType, * FROM Tbl_DocB)
UNION ALL
(SELECT 'C' AS DocType, * FROM Tbl_DocC)
) AS docs
JOIN Tbl_User AS user ON user.UserId = docs.UseriD
JOIN Tbl_Customer AS Customer ON Customer.CustomeriD = docs.CustomeriD
GROUP BY Customer.CustomerID , Customer.CustomerName

Answer 2

You can use common table expressions to get the count for each report type per customer, with conditional aggregation for reports made by a specific user, and join them to the customers table.
Something like this should get you the desired results:
DECLARE #UserId int = 1; -- or whatever the id of the user you need
WITH CTEDocA AS
(
SELECT CustomerID
, COUNT(DocId) As NumberOfReports
, COUNT(CASE WHEN UserId = #UserId THEN 1 END) As NumberOfReportsByUserAzerty
FROM Tbl_DocA
GROUP BY CustomerID
), CTEDocB AS
(
SELECT CustomerID
, COUNT(DocId) As NumberOfReports
, COUNT(CASE WHEN UserId = #UserId THEN 1 END) As NumberOfReportsByUserAzerty
FROM Tbl_DocB
GROUP BY CustomerID
), CTEDocC AS
(
SELECT CustomerID
, COUNT(DocId) As NumberOfReports
, COUNT(CASE WHEN UserId = #UserId THEN 1 END) As NumberOfReportsByUserAzerty
FROM Tbl_DocC
GROUP BY CustomerID
)
SELECT cust.CustomeriD
,cust.CustomerName
,ISNULL(a.NumberOfReports, 0) As NumberOfDocA
,ISNULL(a.NumberOfReportsByUserAzerty, 0) As NumberOfDocAByAzerty
,ISNULL(b.NumberOfReports, 0) As NumberOfDocB
,ISNULL(b.NumberOfReportsByUserAzerty, 0) As NumberOfDocBByAzerty
,ISNULL(c.NumberOfReports, 0) As NumberOfDocC
,ISNULL(c.NumberOfReportsByUserAzerty, 0) As NumberOfDocCByAzerty
FROM Tbl_Customer cust
LEFT JOIN CTEDocA As a
ON cust.CustomeriD = a.CustomerID
LEFT JOIN CTEDocA As b
ON cust.CustomeriD = b.CustomerID
LEFT JOIN CTEDocA As c
ON cust.CustomeriD = c.CustomerID
To filter by date you can add a where clause to each common table expresstion.
BTW, The fact that you have three identical tables for three document types suggest a bad database design.
If these tables are identical you should consider replacing them with a single table and add a column to that table describing the document type.

Answer 3

There are several ways to do this. One key feature needed is to count a particular user apart from the others. This is done with conditional aggregation. E.g.:
select
customerid,
count(*),
count(case when userid = <particular user ID here> then 1 end)
from tbl_doca
group by customerid;
Here is one possible query using a cross join to get the user in question once and cross apply to get the numbers.
select
c.customerid,
c.customername,
doca.total as doc_a_total,
doca.az as doc_a_by_azerty,
docb.total as doc_b_total,
docb.az as doc_b_by_azerty,
docc.total as doc_c_total,
docc.az as doc_c_by_azerty
from tbl_customer c
cross join
(
select userid from tbl_user where username = 'Azerty'
) azerty
cross apply
(
select
count(*) as total,
count(case when da.userid = azerty.userid then 1 end)n as az
from tbl_doca da
where da.customerid = c.customerid
) doca
cross apply
(
select
count(*) as total,
count(case when db.userid = azerty.userid then 1 end)n as az
from tbl_docb db
where db.customerid = c.customerid
) docb
cross apply
(
select
count(*) as total,
count(case when dc.userid = azerty.userid then 1 end)n as az
from tbl_docc dc
where dc.customerid = c.customerid
) docc
order by c.customerid;
Other options would be to replace the cross apply with left outer join and non-correlated subqueries or to put subqueries into the select clause.

Answer 4

Combining the totals for the documents is another method.
Then use conditional aggregation for the counts.
untested notepad scribble:
;WITH SPECIFICUSER AS
(
SELECT UseriD
FROM Tbl_User
WHERE UserName = 'azerty'
),
DOCTOTALS (
SELECT CustomeriD, UseriD, 'DocA' AS Src, COUNT(DocId) AS Total
FROM Tbl_DocA
GROUP BY CustomeriD, UseriD
UNION ALL
SELECT CustomeriD, UseriD, 'DocB', COUNT(DocId)
FROM Tbl_DocB
GROUP BY CustomeriD, UseriD
UNION ALL
SELECT CustomeriD, UseriD, 'DocC', COUNT(DocId)
FROM Tbl_DocC
GROUP BY CustomeriD, UseriD
)
SELECT
docs.CustomeriD,
cust.CustomerName,
SUM(CASE WHEN usrX.UseriD is not null AND docs.Src = 'DocA' THEN docs.Total ELSE 0 END) AS Total_DocA_userX,
SUM(CASE WHEN Src = 'DocA' THEN docs.Total ELSE 0 END) AS Total_DocA,
SUM(CASE WHEN usrX.UseriD is not null AND docs.Src = 'DocB' THEN docs.Total ELSE 0 END) AS Total_DocB_userX,
SUM(CASE WHEN Src = 'DocB' THEN docs.Total ELSE 0 END) AS Total_DocB,
SUM(CASE WHEN usrX.UseriD is not null AND docs.Src = 'DocC' THEN docs.Total ELSE 0 END) AS Total_DocC_userX,
SUM(CASE WHEN Src = 'DocC' THEN docs.Total ELSE 0 END) AS Total_DocC
FROM DOCTOTALS docs
LEFT JOIN Tbl_Customer cust ON cust.CustomeriD = docs.CustomeriD
LEFT JOIN Tbl_User usr ON usr.UseriD = docs.UseriD
LEFT JOIN SPECIFICUSER usrX ON usrX.UseriD = docs.UseriD
GROUP BY docs.CustomeriD, cust.CustomerName
ORDER BY docs.CustomeriD
Those long column names could be set on the report side