How to count something in a mysql procedure? - mysql

Question

I have written a procedure that shows me the image path from picture table and I want to calculate the no. of unread messages.Here is what i am doing
CREATE PROCEDURE datehate.dashboard_message(IN UserID INT)
BEGIN
SELECT picture.path_thumb,status
FROM picture,message,user_profile
WHERE (
(message.receiver_user_id=UserID)
AND
(user_profile.user_id=message.sender_user_id AND picture.picture_id=user_profile.picture_id)
);
END
And this the output i am getting
path_thumb status
E:\DateOrHateUser\DEMO_2_Stockhlom\images\Male\1#j... UNREAD
E:\DateOrHateUser\DEMO_2_Stockhlom\images\Male\3#j... READ
E:\DateOrHateUser\DEMO_2_Stockhlom\images\Male\5#j... UNREAD

Answer 1

use
SELECT count(*)
to get the number of records returned
and put
status="UNREAD"
in your WHERE condition

Answer 2

How about -
CREATE PROCEDURE datehate.dashboard_message(IN UserID INT)
BEGIN
SELECT p.path_thumb, SUM(IF(m.status = 'UNREAD', 1, 0)) AS unread_msgs
FROM message m
INNER JOIN user_profile up
ON m.sender_user_id = up.user_id
INNER JOIN picture p
ON up.picture_id = p.picture_id
WHERE m.receiver_user_id=UserID
GROUP BY m.sender_user_id, p.path_thumb;
END
EDIT I have modified the above query to give the count of unread messages without excluding senders for whom you have no unread messages. Sorry, I misunderstood your question.
or this which will give you the count of messages in each status -
CREATE PROCEDURE datehate.dashboard_message(IN UserID INT)
BEGIN
SELECT p.path_thumb, m.status, COUNT(*) AS msgs
FROM message m
INNER JOIN user_profile up
ON m.sender_user_id = up.user_id
INNER JOIN picture p
ON up.picture_id = p.picture_id
WHERE m.receiver_user_id=UserID
GROUP BY m.sender_user_id, p.path_thumb, m.status;
END