? on joining tables

Barb54

Hi,
I have 2 tables - records table holds the detail and points table holds the values that a form uses to abstract and add to each new record as field info for that member. I then have totals pages that show totals for each member.

If I used a join to create new records in the records table and I change a value(integer) in the points table..............

Question: would ALL records in the records table be affected by this change? or only new records? I just need to clarify this before I do it, lol. I don't want people screaming at me, omg, lol.

Thanks,
Barb

nemonoman

Joins are dynamic. You can join any table to any table based on the content of any column's rows.

All a JOIN does is say: connect these rows wherever these values are equal.

Example

Company

ID/Companyname

1/Company1
2/Compay2
3/Company3

Person

ID/firstname/companyid
1/Joe/1
2/bob/1
3/barb/3
4/nemo/2
5/mike/3

SELECT firstname, companyname
FROM Person, Company
WHERE company.id=companyid

Joe/Comany1
Bob/Company1
barb/Company3
nemo/Company2
mike/Company3

How this works is dynamically:

Let's suppose company3 changes its name to BIG3!
nemo changes his name TheNemester
Barb starts to work for company2

After the values are updated in their respective tables:

SELECT firstname, companyname
FROM Person, Company
WHERE company.id=companyid

Joe/Comany1
Bob/Company1
barb/Company2
TheNemester/Company2
mike/BIG3!!

Make sense?

Barb54

Yes, great explanation. But, say a field changes within the referenced record(integer) but it's NOT the linked field. You are saying the values would be ok, just the link fld change would be seen?

I think the only way I will see this is if I duplicate my database and do a full fledged test. Then I can see what happens in real time. It's been wayyyyy too long since I "created" a database. I spent a lot of years yanking stuff out of databases somebody else set up, lol. I can yank all day long, but the set up has to be right for it all to work together smoothly.

Thanks for your feedback!

Barb