How to get results from sql-jobs without running it every time - sql

Question

I am new to SSC. My scenario is that I have created tables A, B, and C which are related to one another.
Whenever I need data from these three tables I always need to join them to get results. It's a bit time consuming to do this all the time.
Because of this I created a table 'R' and a procedure to update its contents. In this procedure I am joining all the tables (A, B, and C) and storing the result in table R.
To get the results into this table I create a SqlJob which runs once daily. However, there is a problem. Sometimes I want the results from A, B, and C tables where records were inserted recently (before R has been updated).
Is there any solution to get the result from the R table every time without running the SqlJob to update it constantly?
Additional Information
My desired solution is that any time I need data, table R is queried, not the joined tables A, B, and C. Your solution must take this into account.
Thank you.

Answer 1

Instead of running a procedure to constantly update table 'R', create a database view. This view would join A, B, and C together.
Then, any time you need to query A, B, and C, instead of risking getting stale data by querying table R, you would query the view.
I don't know your database schema, so I don't know what fields to join tables A, B, and C on, but it might look something like this:
CREATE VIEW V1
AS
SELECT * FROM A INNER JOIN B ON A.X = B.X INNER JOIN C ON B.Y = C.Y;
To query the view, you would use a SELECT statement just as you would with a table:
SELECT * FROM V1;

Answer 2

add a timex (timestamp) column in your R Table.
so in any time you can get your latest result set.

Answer 3

Based on feedback from the OP that the table 'R' must always be the table queried (is this homework?), then I suppose the only solution would be to place an update trigger on each of the tables 'A', 'B', and 'C' so that when any of these tables are updated their updated contents are automatically placed in table 'R'.
Though inefficient, at least this is better than running a stored procedure on some time basis, for example every 5 minutes.
CREATE PROCEDURE [usp_SyncR]
AS
BEGIN
SET NOCOUNT ON;
UPDATE [R]
SELECT *
GETUTCDATE() as [UpdatedOn]
FROM A INNER JOIN B ON A.X = B.X INNER JOIN C ON B.Y = C.Y
END
CREATE TRIGGER [trg_A_Sync_R]
ON [A]
AFTER Update
AS
BEGIN
EXEC [usp_SyncR];
END
CREATE TRIGGER [trg_B_Sync_R]
ON [B]
AFTER Update
AS
BEGIN
EXEC [usp_SyncR];
END
CREATE TRIGGER [trg_C_Sync_R]
ON [C]
AFTER Update
AS
BEGIN
EXEC [usp_SyncR];
END