在mySQL中，我希望计算不同县的数量

My Table is as follows

- STUDENT TABLE
- STUDENT NAME    -  COUNTY
- John           -  Waterford
- Chris          -  Waterford
- Anne            - Tipperary
- Paul            - Cork
- Thomas         - Cork

Clearly form the table 3 differrent counties exist, I am looking for a count statement to show that three different counties exist.

Currently I am at

SELECT COUNT(county)
FROM Student;

I have tried Grouping and I can seem to count everything in the table bar the number of counties, any help would be great.

use group by

SELECT county,COUNT(county)
FROM Student group by county;

Use DISTINCT to count each county only once:

SELECT COUNT( DISTINCT county)
FROM Student;

Use GROUP BY clause in you query

SELECT COUNT(county) FROM Student GROUP BY `county`;

also you can add DISTINCT as "lad2025" suggested.