Table lookup, to use in a form.

[BDennis]

I�m trying to make a application, and one of the basics is the ability to display several different records frm one db simultaneously in a set called by the parent of the set.
The situation is of one person renting more than one item from a products list.
We use it for:- cost list for rental on invoice for different line items, different drivers/employees for the same company, the same part used for repair of different machines, etc.

eg, one person renting several library books.

I have tried following this (very helpful) message board advice, but I am still stuck.

I have now:-
a person list db.
-linked to: one to many, person number field to linking field.
a linking db, two fields. linking field, and machine number field.
The machine number field of the linking db, has field table lookup to the the db of the machine db.

In that configaration nothing much works, just a browse of the linking field; with it�s two fields.

If I have a further link in the set, one to one from the linking db machine number to the machine db, machine number field it works.
I get the machine details I want from the lookup field. BUT, only for the last record; not for the several I need. If I try one-to-many, nothing.

I am sure I am missing something simple, but not getting it.
Attachments don�t seem to work here I can�t get to print or read them, and I certainly consider myself a newbee at all computor stuff.
This is a continuation of my question;- Sets, using child db twice in form does�nt work dtd approx 1/12/2001

Brian

[David Mason]

RE: Table lookup, to use in a form.

Brian,

The linking of tables is not really hard, but it isn't easy either.

to get a list of what one has rented/sold to a customer, a link something like.

Parent - customer - linked on acct field
one to many
child - machines ( rented/sold items ) - linked on acct field

Once this is done - you can make a browse of machines in your form based on the set to view all rented/sold items to that account.

This is a simple one, but hard if you are new to this.

You may already be way ahead of this but Linking fields is kinda logical - getting the info out is almost the reverse sometimes.

Hope it helps
Dave

[Tom Cone Jr]

RE: Table lookup, to use in a form.

Brian,

Assume three tables:

Customers - contains contact info on each customer
ItemsRented - contains list of items rented by a customer
ProductsList - contains details on each item rented.

Put a customernumber field in Customers and ItemsRented. Use it to link Customers table one to many to ItemsRented.

Put an itemnumber field in ItemsRented and ProductsList.
Use it to link ItemsRented one to one to ProductList.

Your set has a parent table, Customers.
It has a child table ItemsRented
It has a grandchild table ProductsList.

Base your form on the set.

The foregoing assumes you do not want to store the descriptive details for each item inside the ItemsRented table.

In some apps it would be simpler to have a two level set, omitting the grandchild table. However, you've have to store the descriptive information on each item rented inside each ItemsRented record. This could be done using a table lookup to the ProductsList, filling in the desired fields in ItemsRented table.

If this is all greek to you, and you continue to feel like in you're in over your head, there's nothing wrong, but you may want to hire someone to build it for you.

-- tom

[BDennis]

RE: Table lookup, to use in a form.

Tom;

Thanks for your help.
I have done what you suggest and it works as you say. I guess the problem is that is not what I need.

I need the result of one person -taking out many library books/garage car repair -using many parts/one teacher -has many students, etc. etc.
It must be a common requirement.

I do need to display and use the descriptive details of the product list, and so far I can do that either:-

a)-by having a link, one to one, between child linking table and grandchild table. The problem I have with this it only displays one record at one time, logically. I need to display all the records and only those, in the grandchild table that are selected in the parent table. I suppose I could display one record, then copy that info to fields in the parent, then go to the next grandchild record etc. That just seems pretty long-winded for what I want.

b)-by having corresponding fields filled in the child table by the grandchild lookup table, and arranging the pop-up. It seems to want to pop-up all the records in the child linking table, but I guess I can use some filtering to get only what I select in the parent in the pop-up. The problem with that approach seems like I'll end up reproducing all of the grandchild db eventually. That will end up with reproduced, non-current db�s in lots of linking tables thruout the application; and there will be many of them. Keeping each db current will be a nightmare, I thought relational db�s were to avoid that, as well as other things.

I was wondering if there is a practical approach in using either method:-
(a) basically, but using a method to show more that one record in the browse table on the form Is that possible? It seems to me to be the best approach, and having a one to many link from parent to child linking tables I thought would have done it, but I can only get it to show the one record. But it still looks up the grandchild table and retains it unless I would pack it or something afterwards.
I suppose I can use this approach as follows:- instead of a linking table with a corresponding record, one field only, of all the grandchild records, I could use a linking table with only one record in which I fill in the first field from the parent table. Then have the first field post its info to the second field, which then gets the info in one record of the lookup table. I could use a separate linking table, for each parent field which required the info from the granchild db. It seems to me I would be using lookup tables to do the job a relational db, but it should work?

(b) basically, but only to pop-up the selected grandchild records from the parent table, and then afterwards to pack the child linking table to eliminate clutter build up.

(c) I still feel there must be simple approach that I am missing!

Thanks for your time and help.

[Tom Cone Jr]

RE: Table lookup, to use in a form.

Brian,

Why not zip the database you are developing and attach it here for us to see? Include a text file explaining which forms and tables you want to use, and outlining, in detail, what it is you are trying to accomplish... and where it's failing.

-- tom

[Tom Cone Jr]

RE: Table lookup, to use in a form.

Brian,

Here's a simple example of the two level model I described before.

Unzip the attachment to a separate folder. Do not mix it with your development work.

-- tom

[BDennis]

RE: Table lookup, to use in a form.

Hi Tom,

I think I finally have the answer to this. I�m still checking it out and will advise. Your input has been a great help; thanks.

Brian

[Tom Cone Jr]

RE: Table lookup, to use in a form.

That's good news. Let us know what you come up with.

-- tom