Count and distinct count

Question

0.00/5 (No votes)

See more:

I have simple query in which count of distinct chemist id is retrieved for particular user.

if i write -> count(distinct(chemist_id)) -> it returns= 1 [here chemist_id=0]
if i write -> count(chemist_id) -> it returns= 9 (9 times user add other chemist details(not registered chemist details))

how distinct count=1 if id's are 0

Please tell me how it is possible?

Posted 10-Dec-12 17:52pm

Sweetynewb

Add a Solution

Comments

choudhary.sumit 11-Dec-12 0:06am

post your full query with some table records fro example.

Sweetynewb 11-Dec-12 0:33am

Query:

select count(distinct(cb.chemist_name)) as SumChem
from educator_call_dtls ed
left join chem_business_data cb on cb.call_id=ed.call_id
where ed.eid=780 and month(ed.call_date)=11 and year(ed.call_date)=2012

Table:chem_business_data has 9 records:

ID chem_id call_id patient_count other_chemist_name location
46367 0 64866 0 MEDICAL SHOP DEVICE DEMO SALEM
46368 0 64869 0 MEDICAL SHOP DEVICE DEMO SALEM
48741 0 67806 0 MEDICAL SHOP DEVICE DEMO SALEM
48750 0 67812 0 MEDICAL SHOP DEVICE DEMO SALEM
48749 0 67810 0 CANOPY ERODE
49790 0 69546 0 MEDICAL SHOP DEVICE DEMO SALEM
51811 0 71874 0 MEDICAL SHOP DEVICE DEMO SALEM
51867 0 71912 0 MEDICAL SHOP DEVICE DEMO SALEM
51808 0 71869 0 MEDICAL SHOP DEVICE DEMO SALEM

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

nagalkumar · Answer 1 · 2012-12-10T18:10:00

Solution 1

Hi,

Count(chemist_id) - returns count of rows in the table

count(distinct chemist_id) - returns count of distinct (or unique) chemist_id. Which means all rows in the table have same chemist_id.

Posted 10-Dec-12 18:10pm

nagalkumar

Updated 10-Dec-12 18:16pm

v4

Prasad Guduri · Answer 2 · 2012-12-11T00:56:00

Solution 2

-- For Better Understanding--

Chem_id (0,0,0,0,1,1,1,4,4,4,4,4)
Count(Chem_id)=12
Count(Distinct(Chem_id))=3 ( Here 0,1,4)

Posted 11-Dec-12 0:56am

Prasad Guduri