COUNT

Returns the number of records in the resultset/group. When used with the optional DISTINCT keyword, returns the unique number of records in the resultset/group.  

 

This parameter can be either an asterisk (*) or an expression.  If an asterisk is used then all rows of the resultset/group are counted regardless of NULL status.  If the expression for a row evaluated to NULL, it will not be counted.

 

Example:

With the sample data set:

 

Field1

Field2

Field3

23

10

17

17

10

9

5

12

15

 

 

SELECT COUNT(Field2) returns 3.
 
SELECT COUNT(Distinct Field2) returns 2.