SQL query - divide two numbers from same column - sql

Question

I am using a hosted SQL 2008 database (so can't create tables or modify values) and would like to divide two numbers from the same column to get a single percentage answer. The values are entered into the same column (TA_ANS_ANSWER) but the value entered is based on another field, the question (TA_ANS_QUESTION).
e.g. for this month;
First question - "Total No. Contractors on e-learning User List" - Answer entered '430'.
Second question - "Total No. Contractors on e-learning inducted report" - Answer entered '357'
I need to get the value 83% for the above.
I need to calculate a single percentage value for each Month as the answers get populated.
The query below gives the base query which returns the name of the previous MONTH (e.g. Nov), PPM ID and Answer (e.g. 430). I can modify this to return both rows, 1 for each question answered but I only want a single row with the Month, PPM ID and Percentage calculation.
Apologies if the answer is staring me in the face but any help would be greatly appreciated.
SELECT CONVERT(varchar(3), TA_DUE_DATE-28, 100) AS MONTH,
TA_TASK_ID AS PPM,
F_TASK_ANS.TA_ANS_ANSWER AS ANSWER
FROM F_TASK_ANS
INNER JOIN F_TASKS
ON F_TASK_ANS.TA_ANS_FKEY_TA_SEQ = F_TASKS.TA_SEQ
WHERE TA_ANS_ANSWER <> ''
AND F_TASKS.TA_FKEY_CTR_SEQ = 126
AND F_TASK_ANS.TA_ANS_QUESTION LIKE '%Total No. Contractors on e-learning User List%'
AND (TA_HIST_STATUS IS NULL OR TA_HIST_STATUS = 'COMPLETE')
AND TA_TASK_ID LIKE '%6025'
AND TA_DUE_DATE >= GETDATE()-360
AND TA_DUE_DATE <= GETDATE()+7
ORDER BY PPM

Answer 1

What you are looking for is called a pivot. This can be done with the PIVOT keyword, or it can be done manually with GROUP BY and MIN(CASE WHEN ... END). Check out other answers tagged with "pivot" for more examples.
SELECT CONVERT(varchar(3), TA_DUE_DATE-28, 100) AS MONTH,
TA_TASK_ID AS PPM,
MIN(CASE WHEN F_TASK_ANS.TA_ANS_QUESTION LIKE '%Total No. Contractors on e-learning inducted report%' THEN F_TASK_ANS.TA_ANS_ANSWER END) +0.0
/ MIN(CASE WHEN F_TASK_ANS.TA_ANS_QUESTION LIKE '%Total No. Contractors on e-learning User List%' THEN F_TASK_ANS.TA_ANS_ANSWER END)
AS PERCENTAGE
FROM F_TASK_ANS
INNER JOIN F_TASKS
ON F_TASK_ANS.TA_ANS_FKEY_TA_SEQ = F_TASKS.TA_SEQ
WHERE TA_ANS_ANSWER <> ''
AND F_TASKS.TA_FKEY_CTR_SEQ = 126
AND (F_TASK_ANS.TA_ANS_QUESTION LIKE '%Total No. Contractors on e-learning User List%' OR
(F_TASK_ANS.TA_ANS_QUESTION LIKE '%Total No. Contractors on e-learning inducted report%')
AND (TA_HIST_STATUS IS NULL OR TA_HIST_STATUS = 'COMPLETE')
AND TA_TASK_ID LIKE '%6025'
AND TA_DUE_DATE >= GETDATE()-360
AND TA_DUE_DATE <= GETDATE()+7
GROUP BY CONVERT(varchar(3), TA_DUE_DATE-28, 100),TA_TASK_ID

Answer 2

One possible answer is to use a Common Table Expression (CTE). Something like this:
;with TotalOnELearningList (Month, TaskID, NumberOnList) as
(
select
convert(varchar(3), ta_due_date - 28, 100) as month,
ta_task_id,
f_task_ans.ta_ans_answer
from ...
),
TotalOnInductedReport (Month, TaskID, NumberInductedReport) as
(
...
),
select
case NumberInductedReport when 0 then 0 else NumberOnList / NumberInductedReport * 100 end as 'Percent',
...
from TotalOnELearningList
inner join TotalOnIndutedReport
on...