MySQL Procedure (help)

Question

I have several tables in my database such as

comments status events

I’m trying to create an SQL query procedure which counts data from these different tables based on the userID entered and then sum up the counts to create a unique valued. This is what i’ve tried so far but i’m having problems with the syntax. Where am I going wrong??

SELECT COUNT(user_id) AS comments FROM comment
WHERE user_id= userID
UNION ALL
SELECT COUNT(creator_id) AS events FROM event
WHERE creator_id=userID;

Answer 1

In a union, the fields are combined based on order. So giving the count field a different name in each part of the union does not make two fields. It becomes the same field in the end. To differentiate which value came from which table, add a hardcoded string literal like so:

SELECT COUNT(user_id) AS rows, 'comment' as tablename FROM comment
WHERE user_id= userID
UNION ALL
SELECT COUNT(creator_id) AS rows, 'event' as tablename FROM event
WHERE creator_id=userID;