Question

I have a typical LAMP based site + Zend Framework where I have a base table and a summary table. Summary table is used to display data in reports.

Base table –

ID | Status
1 | 1
2 | 1
3 | 2
4 | 2
5 | 1
6 | 1

Summary table –

Status | Count
1 | 4
2 | 2

The base table will be changed(insert,update,delete) at an average of 20 times per day.

Currently, I am using triggers to call a stored procedure which will update the summary table based on the base table.

This is the stored procedure.

CREATE PROCEDURE UpdateSummary()

BEGIN

UPDATE summary a

INNER JOIN

(SELECT status, count(*) c from base group by status) b

ON a.status = b.status

SET a.count = b.c;

END

And I have 3 triggers (one for each – Insert, Delete and Update). I have shown the insert sample alone below. Other are similar to this.

CREATE TRIGGER S_T_TRIGGER_I

AFTER INSERT ON base

FOR EACH ROW

CALL UpdateSummary();

I want the summary table to be updated to the latest values always.
Using triggers and stored procedure like this is the best way or is there a elegant way to do this?

Answer 1

Why don’t you use a view like :

 CREATE VIEW Summary AS 
      SELECT status, count(*)
      FROM Base
      GROUP BY status;

Each time you need, just do :

SELECT * 
FROM Summary 

And you’ll get your result in real time (each call re-computed).

Views can be used the same way like table is used in Zend Framework. Just that you need to specify a primary key explicitly as explained here