CODEWITHSUNDEEP
sqlms-access
Manas Saha
Manas Saha

Reputation: 1497

Need to calculate percentage of total count in SQL Query

I have a a table where I have two columns, one is a Date Time column (Test_Complete) and another is alphanumeric Record ID column (RecordID).

I need to prepare a count of recordIDs which were processed on a monthly basis. I have already created a query for that.

SELECT (Format([Test_Complete],"mmm"" '""yy")) AS Evaluation_Month, 
Count(tbl_TestStatus.Record_ID) AS CountOfRecord_ID
FROM tbl_TestStatus
WHERE (((tbl_TestStatus.[Test_Complete]) Is Not Null))
GROUP BY (Format([Test_Complete],"mmm"" '""yy")),
(Year([Test_Complete])*12+Month([Test_Complete])-1);

This query works well and gives me output like this:

Evaluation_Month     CountOfRecord_ID
------------------   -----------------
 Jan'12                   20
 Feb'12                   90
 Mar'12                   40
 Apr'12                   50

Now what I need is to calculate the percentage of CountOfRecord_ID value against each Evaluation_Month and append the percentage with the value in Evaluation_Month data.

In the above resultset, the sum of all the CountOfRecord_ID is 200. so the percentage needs to be calculated considering 200 as 100%, such that my result looks like this:

Evaluation_Month     CountOfRecord_ID
------------------   -----------------
 Jan'12 (10%)                20
 Feb'12 (45%)                90
 Mar'12 (20%)                40
 Apr'12 (25%)                50

How can I modify my SQL query to achieve this?

Upvotes: 1

Views: 16281

Answers (1)

Barranka
Barranka

Reputation: 21047

You only need to add a "subquery field" in your select statement with the total count of records. Something like this:

SELECT 
    (Format([Test_Complete],"mmm"" '""yy")) AS Evaluation_Month, 
    Count(tbl_TestStatus.Record_ID) AS CountOfRecord_ID,
    Count(tbl_TestStatus.Record_ID) / (select count(tbl_testStatus.recordId
     from tbl_testStatus
     where tbl_testStatus.test_complete is not null) as percent
FROM 
    tbl_TestStatus
WHERE 
    (((tbl_TestStatus.[Test_Complete]) Is Not Null))
GROUP BY 
    (Format([Test_Complete],"mmm"" '""yy")),
    (Year([Test_Complete])*12+Month([Test_Complete])-1);

Upvotes: 3

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