Hi friends,

My table Employees contain 4 Columns:
1. EmpID
2. EmpName
3. EmpAddress &
4. DeptID
EmpName,EmpAddress & DeptID can contain duplicate records. In my table DeptID & EmpName has duplicates values. Then what should be the output of the following queries:

1. SELECT count(1) FROM Employees;
2. SELECT count(distinct 4) FROM Employees;
3. SELECT count(5) FROM Employees;
4. SELECT count(100) FROM Employees;

In all above queries, what is 1 or 4 or 5 or 100 ? If these are column numbers then what will be the output of the 4th query.

In case of query no. 1, 3 & 4, result is total no of rows present in the table. & In case of query 2, result is 1(u can place any number in place of 4).

Pls give me a proper solution...
I m really confusing ..

it's easy, take away count
run this
SELECT 1 FROM Employees;
SELECT 4 FROM Employees;
SELECT 5 FROM Employees;
SELECT 100 FROM Employees;

as you can see the result is a bunch of numbers that are always the same
when you do distinct
for example
SELECT distinct 100 FROM Employees;
you only get one row, that's why when you do count(distinct 4) you get 1



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Thank you sir.
I hav sent a very good solution.