Q:

How to find the rows from a table which has exactly two 'n' s in the employee name?

I want to find all the employees whose names have exactly two n's in their name. How can this be done?

A:

something like this should be enough:
select * from employee_table where Length(lastname) - length(replace(lastname, 'n','')) = 2

be aware that may cause a full table scan :-)

