Golgappa.net | Golgappa.org | BagIndia.net | BodyIndia.Com | CabIndia.net | CarsBikes.net | CarsBikes.org | CashIndia.net | ConsumerIndia.net | CookingIndia.net | DataIndia.net | DealIndia.net | EmailIndia.net | FirstTablet.com | FirstTourist.com | ForsaleIndia.net | IndiaBody.Com | IndiaCab.net | IndiaCash.net | IndiaModel.net | KidForum.net | OfficeIndia.net | PaysIndia.com | RestaurantIndia.net | RestaurantsIndia.net | SaleForum.net | SellForum.net | SoldIndia.com | StarIndia.net | TomatoCab.com | TomatoCabs.com | TownIndia.com
Interested to Buy Any Domain ? << Click Here >> for more details...

  1. Categories >> Software >> Databases >> SQL Server
  2. Suggest New Category

What is the difference between the following two sql
statements
select count(*) from <tablename>
select count(col_name) from <tablename>

Question Posted / srikanth

Answers were Sorted based on User's Feedback



What is the difference between the following two sql statements select count(*) from <tablena..

Answer / debasis

select count(*) from <tablename> returns the number of rows
in the table.

select count(col_name) from <tablename> return number
values in the column (Ignores null value in the colum). For
example if we execute the following 2 queries then

select count(*) form emp
select count(comm) form emp

The result will be
14
4

Is This Answer Correct ?    34 Yes 7 No

What is the difference between the following two sql statements select count(*) from <tablena..

Answer / kushi

for the First Qry,result is "No.of records"
for the second Qry,result is "No.of records for particular
columnname"

Is This Answer Correct ?    17 Yes 0 No

What is the difference between the following two sql statements select count(*) from <tablena..

Answer / sandeep

select count(*) from <tablename>
- return number of records from table


select count(col_name) from <tablename>
- return number of records where col_name is NOT NULL
- Null value is eliminated by an aggregate or other SET
operation.

Is This Answer Correct ?    5 Yes 0 No

What is the difference between the following two sql statements select count(*) from <tablena..

Answer / sql2000

There seem to be a problem with the solutions provided by
the above.

Both the counts should provide the same result which is the
no of rows in the table.
count (*) will result in a bigger table scan than count
(col_name) hence its advisable to use count(1) while
calculating the count for a table.

Correct me if I am wrong...:)

Is This Answer Correct ?    1 Yes 3 No

What is the difference between the following two sql statements select count(*) from <tablena..

Answer / karthik

both will be display same record count.

Is This Answer Correct ?    2 Yes 12 No

Post New Answer

More SQL Server Interview Questions

How is sql server used?

0 Answers  

what is a schema in sql server 2005? Explain how to create a new schema in a database? : Sql server database administration

0 Answers  

You have modified 100 store procedures and want to replicate these changes from development to prodution, and production can have users using the Server/DB, how would you replicate without causing issues?

0 Answers  

Types of Authentications in Sql Server? How user gets authenticated through windows authentication?

0 Answers   MCN Solutions,

What is the bookmark lookup and rid lookup?

0 Answers  

What is the maximum size per database for sql server express?

0 Answers  

What is the use of sql profiler in sql server 2012?

0 Answers  

How to get a list of columns using the "sp_help" stored procedure in ms sql server?

0 Answers  

How many full-text indexes can a table have?

0 Answers  

What are the different types of normalization?

0 Answers  

Is it possible to create trigger on views?

0 Answers  

In which files does sql server actually store data?

0 Answers  

For more SQL Server Interview Questions Click Here
Categories