Question

project table

proj_id, proj_name, Proj_Type
1, test, dev
2, test1, infra
3, test2, BI

quota table

quota_id, proj_id, allot_type, allot_num
1, 1, java, 3
2, 1, architect, 1
3, 1, Jasper, 2
4, 2, unix admin, 2
5, 2, dba, 1
6, 2, nwk admin, 1

tracking table

track_id, proj_id, status,start_date, sch_end_date,end_date, update_date
1,1, started,dec 16 2012,feb 12 2013,,01 jan 2013
2,2, resource allocated, 01 jan 2013, 03 mar 2013, , 01 jan 2013
3,3, yet to start, 19 jan 2013, 19 apr 2013

Destination table (Summary_Table)

event_id, proj_id, proj_name, Proj_Type, allot_type, allow_num, proj_start_date_sch_end_date, proj_status
1, 1, test,dev,java,3,16 dec 2012,12 feb 2013,started
2, 1, test,dev,architect,1,16 dec 2012, 12 feb 2013, started
3, 1, test,dev,jasper, 2, 16 dec 2012, 12 feb 2013, started

I have to write a stored procedure to load the destination table with the information from all three source tables

and another procedure to update the records regularly in destination table when ever there is a change in source tables such as project status changed from started to delivered etc.

Can some one give me some sample procedures to achieve above please.

Answer 1

Load destination table

• The store procedure will run only once – i.e. just to populate destination table?

• Or for each insert in any of the three sources table will have to insert in destination table too?

  Just for loading just use a stored procedure

  INSERT INTO desitination ([columns])
  SELECT [columns]
  FROM project
  JOIN quota ON …
  JOIN tracking ON …

For your second procedure – update destination table if there are any changes in source table, i would suggest to use triggers on update i.e.

• set trigger for update on source tables that will update destination table records
  (http://dev.mysql.com/doc/refman/5.0/en/triggers.html)

If you have to fill destination table each time when insert occurred in one of the source tables than will have to set a trigger for insert and update.

If the inserts/updates are not at the db level, like you have any application that is interacting with db, then setting a stored procedure to handle updates on destination table might work.

If you will provide the tables schema and some dummy data i can create a sample code.

CREATE TABLE `project` (
  `proj_id` int(11) NOT NULL AUTO_INCREMENT,
  `proj_name` varchar(30) NOT NULL,
  `Proj_Type` varchar(30) NOT NULL,
  PRIMARY KEY (`proj_id`)
);

CREATE TABLE `quota` (
  `quota_id` int(11) NOT NULL AUTO_INCREMENT,
  `proj_id` int(11) NOT NULL,
  `allot_type` varchar(30) NOT NULL,
  `allot_num` INT(11) NOT NULL,
  PRIMARY KEY (`quota_id`)
);

CREATE TABLE `tracking` (
  `track_id` int(11) NOT NULL AUTO_INCREMENT,
  `proj_id` int(11) NOT NULL,
  `status` varchar(30) NOT NULL,
  `start_date` DATE NULL,
  `sch_end_date` DATE NULL,
  `end_date` DATE NULL,
  `update_date` DATE NULL,
  PRIMARY KEY (`track_id`)
);

CREATE TABLE `Destination` (
  `event_id` int(11) NOT NULL AUTO_INCREMENT,
  `proj_id` int(11) NOT NULL,
  `proj_name` varchar(30) NOT NULL,
  `Proj_Type` VARCHAR(30) NOT NULL,
  `allot_type` varchar(30) NOT NULL,
  `allot_num` INT(11) NOT NULL,
  `proj_start_date_sch_end_date` DATE NULL,
  `status` varchar(30) NOT NULL,
  PRIMARY KEY (`event_id`)
);


INSERT INTO `project` (`proj_id`, `proj_name`, `Proj_Type`) VALUES
(1, 'test', 'dev'),
(2, 'test1', 'infra'),
(3, 'test2', 'BI');

INSERT INTO `quota` (`quota_id`, `proj_id`, `allot_type`, `allot_num`) VALUES
(1, 1, 'java', 3),
(2, 1, 'architect', 1),
(3, 1, 'Jasper', 2),
(4, 2, 'unix admin', 2),
(5, 2, 'dba', 1),
(6, 2, 'nwk admin', 1);

INSERT INTO `tracking`(`track_id`, `proj_id`, `status`, `start_date`, `sch_end_date`, `end_date`, `update_date`) VALUES 
(1, 1, 'started', '2012-12-16', '2013-02-12', NULL, '2013-01-01'),
(2, 2, 'resource allocated', '2013-01-01', '2013-03-03', NULL, '2013-01-01'),
(3, 3, 'yet to start', '2013-01-19', '2013-04-19', NULL, NULL);


delimiter $
CREATE TRIGGER `uProjectChange` AFTER UPDATE ON project
FOR EACH ROW BEGIN

    UPDATE `test`.`Destination` AS d 
  INNER JOIN `test`.`project` AS p ON p.proj_id = d.proj_id 
  SET 
    d.proj_name = p.proj_name,
    d.Proj_Type = p.Proj_Type;

END;$
delimiter ;


-- Load destination table
INSERT INTO `Destination` (`proj_id`, `proj_name`, `Proj_Type`, `allot_type`, `allot_num`, `proj_start_date_sch_end_date`, `status`) 
SELECT 
    p.proj_id, p.proj_name, p.Proj_Type, 
    q.allot_type, q.allot_num,
    t.start_date, t.status
FROM 
    project p 
INNER JOIN quota q ON q.proj_id = p.proj_id 
INNER JOIN tracking t ON t.proj_id = q.proj_id;

-- UPDATE project SET  proj_name = 'test_test', Proj_Type = 'dev_test' WHERE proj_id = 1;
-- UPDATE project SET  proj_name = 'test', Proj_Type = 'dev' WHERE proj_id = 1;
SELECT * FROM `project`;
SELECT * FROM `Destination`;

http://sqlfiddle.com/#!8/43c77/1

Here is the sample code – but i do have a question – why using destination table i.e. have a table, why you are not using a view instead?