What is count(*) in SQL?

Question

Can anyone explain what is count(*) in SQL?

Answer 1

In SQL, count (*) does not take parameters and returns the total number of rows in a particular table. The difference between COUNT (*) and COUNT (ALL) is that COUNT (*) also counts NULL values and duplicates but COUNT (ALL) does count only unique and non-null values.

The following SQL query returns the total number of employees from the employee table:

SELECT COUNT (*)

FROM Employee;

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