MySQL: How to count rows when multiple joined tables? - mysql

Question

MySQL: How to count rows when multiple joined tables ??
+Query:
SELECT p.role FROM users u
INNER JOIN roles r ON r.id=u.role
INNER JOIN permissions p ON p.role=r.id
WHERE p.p_id=19 AND p.p_update=1 AND r.active=1
GROUP BY p.role
+Result:
________
|p_role:|
|_______|
| 1 |
| 4 |
|_______|
When I add COUNT() function to p.role:
+Query:
SELECT COUNT(p.role) FROM users u
INNER JOIN roles r ON r.id=u.role
INNER JOIN permissions p ON p.role=r.id
WHERE p.p_id=19 AND p.p_update=1 AND r.active=1
GROUP BY p.role
+Result:
_______________
|COUNT(p_role):|
|______________|
| 5 |
| 1 |
|______________|
Why I see 2 records I already use COUNT() function??
I don't want to see result like this.
I want to count rows of query above.
I want to see result like this:
_______________
|COUNT(p_role):|
|______________|
| 2 |
|______________|
Please anyone help me. Thanks in advance!
Sorry for my broken English.

Answer 1

Because of GROUP BY clause in your query, it returns count per p.role value. If you want the query to return one value, you can remove GROUP BY, e.g.:
SELECT COUNT(DISTINCT(p.role)) FROM users u
INNER JOIN roles r ON r.id=u.role
INNER JOIN permissions p ON p.role=r.id
WHERE p.p_id=19 AND p.p_update=1 AND r.active=1;
By the way, I have added DISTINCT to the query so that it will return count of distinct p.role values. If you want the count of records only, you can remove DISTINCT.