Solved

SQL Server count function

Posted on 2011-09-23
3
270 Views
Last Modified: 2012-05-12
Hi experts,

I can't tell the difference between these two selects, could you help me understand why they would behave differently?

1. select process_Step, loan_status, count(acct#) from LMDev.dbo.sd10_View_Staging group by process_step, loan_status

2. select process_Step, loan_status, count(*) from LMDev.dbo.sd10_View_Staging group by process_step, loan_status

Thanks!
0
Comment
Question by:JC_Lives
3 Comments
 
LVL 8

Expert Comment

by:Crashman
ID: 36589960
the first count one column, the second count the entire table
0
 
LVL 51

Accepted Solution

by:
HainKurt earned 500 total points
ID: 36589993
check this sample

count(col) counts not null records
count(*) = count(1) counts all rows
a    b
---------
null 1
2    null
null 3

with c as (
select null a, 1 b
union select 2, null
union select null, 3)
select count(a), count(b), COUNT(*), COUNT(1) from c

1	2	3	3

Open in new window

0
 

Author Closing Comment

by:JC_Lives
ID: 36590005
Cool! Thanks!
0

Featured Post

What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

In this article I will describe the Detach & Attach method as one possible migration process and I will add the extra tasks needed for an upgrade when and where is applied so it will cover all.
This article explains how to reset the password of the sa account on a Microsoft SQL Server.  The steps in this article work in SQL 2005, 2008, 2008 R2, 2012, 2014 and 2016.
Via a live example, show how to extract insert data into a SQL Server database table using the Import/Export option and Bulk Insert.
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…

776 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question