SQL Server : group by calculated column - sql

Question

I have a table with columns like this:
I want to know the average compliance rate for every question for that period.
I am passing start dates and end dates as parameters to query.
So if I want for two periods I am passing #StartDate (e.g. 1/6/17) and #EndDate (e.g. 30/6/17) for first period and #StartDate2 (1/10/17) and #EndDate2 (31/10/17) for second period.
My SQL query is:
;WITH tmpTab AS
(
SELECT
question,
SUM((CASE WHEN AnswerValue = 1 THEN 1 ELSE 0 END)) Met,
SUM((CASE WHEN AnswerValue = 3 THEN 1 ELSE 0 END)) NA,
SUM((CASE WHEN (ISNULL(AnswerValue,3) <> 3) THEN 1 ELSE 0 END)) MetNotMet,
DATENAME(DAY, #StartDate) + ' ' + DATENAME(MONTH, #StartDate) + ' ' +
DATENAME(YEAR, #StartDate) + ' To ' + DATENAME(DAY,#EndDate) + ' ' +
DATENAME(MONTH, #EndDate) + ' ' + DATENAME(YEAR, #EndDate) AS RepMonthAndYear
FROM
tableA
WHERE
startdate >= #StartDate AND endate <= #EndDate
GROUP BY
Question
UNION ALL
SELECT
question,
SUM((CASE WHEN AnswerValue = 1 THEN 1 ELSE 0 END)) Met,
SUM((CASE WHEN AnswerValue = 3 THEN 1 ELSE 0 END)) NA,
SUM((CASE WHEN (ISNULL(AnswerValue,3) <> 3) THEN 1 ELSE 0 END)) MetNotMet,
DATENAME(DAY,#StartDate2)+' '+DATENAME(MONTH,#StartDate2)+' '+DATENAME(YEAR,#StartDate2)+ ' To ' + DATENAME(DAY,#EndDate2)+' '+DATENAME(MONTH,#EndDate2)+' '+DATENAME(YEAR,#EndDate2) AS RepMonthAndYear
FROM
tableA
WHERE
startdate >= #StartDate2 AND endate <= #EndDate2
GROUP BY
Question
)
SELECT
Question, Met, NA, MetNotMet,
CASE WHEN (Met) = 0 THEN 0 ELSE ROUND(((CONVERT(FLOAT,(Met))/(MetNotMet))* 100),4) END as CompRate
FROM
tmpTab
In this SQL query, I need to group by RepMonthAndYear column also which I can not do as it is a calculated column. I get an error "invalid column".
And if I use this GROUP BY clause:
(DATENAME(DAY,#StartDate2)+' '+DATENAME(MONTH,#StartDate2)+' '+DATENAME(YEAR,#StartDate2)+ ' To ' + DATENAME(DAY,#EndDate2)+' '+DATENAME(MONTH,#EndDate2)+' '+DATENAME(YEAR,#EndDate2) )
I get this error:
Each GROUP BY expression must contain at least one column that is not an outer reference.
How can I solve this problem?
Is there any other way to know average rate group by particular periods?

Answer 1

Given the following Test Data and your SQL I get what you discibe.
CREATE TABLE tableA (
question VARCHAR(50),
AnswerValue INT,
startdate DATE,
endate DATE
);
INSERT INTO tableA VALUES ('Question A', 1, '2017-06-25', '2017-06-26');
INSERT INTO tableA VALUES ('Question A', 1, '2017-06-27', '2017-06-27');
INSERT INTO tableA VALUES ('Question A', 2, '2017-06-27', '2017-06-27');
INSERT INTO tableA VALUES ('Question B', 1, '2017-06-11', '2017-06-12');
INSERT INTO tableA VALUES ('Question B', 2, '2017-06-13', '2017-06-13');
INSERT INTO tableA VALUES ('Question B', 1, '2017-06-13', '2017-06-13');
INSERT INTO tableA VALUES ('Question C', 1, '2017-06-20', '2017-06-20');
INSERT INTO tableA VALUES ('Question C', 1, '2017-06-23', '2017-06-23');
INSERT INTO tableA VALUES ('Question D', 2, '2017-06-01', '2017-06-01');
INSERT INTO tableA VALUES ('Question E', 1, '2017-10-11', '2017-10-11');
INSERT INTO tableA VALUES ('Question E', 1, '2017-10-15', '2017-10-15');
INSERT INTO tableA VALUES ('Question F', 1, '2017-10-20', '2017-10-20');
INSERT INTO tableA VALUES ('Question F', 2, '2017-10-20', '2017-10-20');
INSERT INTO tableA VALUES ('Question F', 2, '2017-10-20', '2017-10-20');
INSERT INTO tableA VALUES ('Question G', 1, '2017-10-26', '2017-10-26');
INSERT INTO tableA VALUES ('Question H', 1, '2017-10-26', '2017-10-26');
INSERT INTO tableA VALUES ('Question H', 2, '2017-10-26', '2017-10-26');
INSERT INTO tableA VALUES ('Question I', 1, '2017-10-26', '2017-10-26');
Here the outcome of your Query:
Question A 2 0 3 66,6667
Question B 2 0 3 66,6667
Question C 2 0 2 100
Question D 0 0 1 0
Question E 2 0 2 100
Question F 1 0 3 33,3333
Question G 1 0 1 100
Question H 1 0 2 50
Question I 1 0 1 100
I could simplify your SQL and have removed some code duplicates, maybe that was your intended question.
DECLARE #StartDate DATE = '2017-06-01';
DECLARE #EndDate DATE = '2017-06-30';
DECLARE #StartDate2 DATE = '2017-10-01';
DECLARE #EndDate2 DATE = '2017-10-30';
WITH
periods AS (
SELECT #StartDate as startdate,
#EndDate as enddate
UNION
SELECT #StartDate2 as startdate,
#EndDate2 as enddate
)
SELECT t.Question, t.Met, t.NA, t.MetNotMet,
CASE WHEN (t.Met) = 0 THEN 0 ELSE ROUND(((CONVERT(FLOAT,(t.Met))/(t.MetNotMet))* 100),4) END as CompRate
FROM (SELECT question,
SUM((CASE WHEN AnswerValue = 1 THEN 1 ELSE 0 END)) Met,
SUM((CASE WHEN AnswerValue = 3 THEN 1 ELSE 0 END)) NA,
SUM((CASE WHEN (ISNULL(AnswerValue,3) <> 3) THEN 1 ELSE 0 END)) MetNotMet
FROM tableA AS a
JOIN ( SELECT p.startdate,
p.enddate,
DATENAME(DAY, p.startdate) + ' ' + DATENAME(MONTH, p.startdate) + ' ' +
DATENAME(YEAR, p.startdate) + ' To ' + DATENAME(DAY, p.enddate) + ' ' +
DATENAME(MONTH, p.enddate) + ' ' + DATENAME(YEAR, p.enddate) AS RepMonthAndYear
FROM periods p ) AS p ON a.startdate >= p.startdate AND a.endate <= p.enddate
GROUP BY a.Question, p.RepMonthAndYear) AS t