Modify query to group by client identifier - sql

Question

I have the following query.
Base query
WITH CTE (clientid, dayZero)
AS
-- Define the CTE query.
(
SELECT
clientid,
DATEDIFF(
DAY,
MIN(calendar),
MIN(CASE
WHEN total = 0
THEN calendar
END)
) as dayZero
FROM (
SELECT
clientid,
CONVERT(datetime, convert(varchar(10), calendar)) calendar,
TOTAL
FROM STATS s1
) a
GROUP BY clientid
),
cteb as
-- Define the outer query referencing the CTE name.
(SELECT cte.*, c.company, v.Name, m.id as memberid
FROM CTE
JOIN client c
on c.id = cte.CLIENTID
join Domain v
on v.Id = c.domainID
join subscriber m
on m.ClientId = c.id
join activity a
on m.id = a.memberid
where c.id != 023
),
ctec as
(
select count(distinct memberid) as Number from cteb
group by clientid
)
select clientid, dayzero, company, name, Number from cteb , ctec
The output of this query is -
clientid dayzero company name Number
21 35 School Boards Education 214
21 35 School Boards Education 214
I want it to only return 1 row per client. Any ideas on how to modify this query
Sub Query
select count(distinct memberid) as Number from cteb
group by clientid
When I only run the query until the above subquery and select like so -
select * from ctec
where clientid = 21
I get
clientid Number
21 214
22 423
This is what I would. But when I run the following select to get all the other columns I need, I start getting duplicates. The output makes sense because I am not grouping by clientid. But if I groupby how do I get the other columns I need?
select clientid, dayzero, company, name, Number from cteb , ctec
UPDATE
When I run the below select
select clientid, dayzero, company, name, Number from cteb , ctec
group by clientid, dayzero, company, name, Number
I still get
clientid dayzero company name Number
21 35 School Boards Education 214
21 35 School Boards Education 215
I don't understand why I am getting different numbers in the Number column (214 and 215 in this case). But when I run it with the group by as shown below, I get the correct numbers.
select count(distinct memberid) as Number from cteb
group by clientid
select * from ctec
where clientid = 21
I get
clientid Number
21 2190
Neither 214 nor 215 is correct. The correct number is 2190 which I get when I groupby as shown above.

Answer 1

If you want to show unique rows based on a particular column, you can use ROW_NUMBER() like following query.
select * from
(
select clientid, dayzero, company, name, Number,
ROW_NUMBER() OVER(PARTITION BY clientid ORDER BY Number DESC) RN
from cteb , ctec
) t
where RN=1