How to avoid duplicate entries to a simple table?

[BDennis]

RE: How to avoid duplicate entries to a simple tab

Tom and Vince,
Thanks to oth of you for helping me out.
Tom,
From what I understand, I should have another field on the table which would combine (concatenate ?) the two existing fields. I should then compare any new record for existing records just using that field, rejecting a new entry with a message if there exists an existing record with that combination.
I don't quite see how that one field will have all the info of the two other fields, but I'll certainly believe you. (I'm not familiar with the word, let alone concept, of concatenate) eg. Will it differenciate between two records having fields of(a) 54 + 53, and (b)53 + 54.
Would it be practical to have the table as is, add the new field to concatenate the two existing fields, and have the value in the new field as a result of field rules using the existing two fields?
In practise the existing fields are numeric permiting 6 digits each.

Thanks once again for the great help.

Brian.

[Vince McGinnis]

RE: How to avoid duplicate entries to a simple tab

Brian and Tom,

I think I see what the bug is that is causing all the trouble with the Key_Unique().

First of all let me say, I have been able to use the Key_Unique() function with multiple fields, but here's the problem.

The bug seems to only occur when you trim trailing blanks from character fields. For example: Creating an index like:

LastName + FirstName + Company will work fine when used with Key_Unique().

but:

LastName - FirstName - Company will not work

neither will:

Trim(LastName) + Trim(FirstName) + Trim(Company)

Brian, with your data, an index such as:

STR(clino) + STR(firmno) will work will Key_Unique().

But as you know:

Alltrim(STR(clino)) + Alltrim(STR(firmno)) will not work with the Key_Unique()function.

Could someone else test this out?

Hope this helps.

[Tom Cone Jr]

RE: How to avoid duplicate entries to a simple tab

Brian,

Vince was right. Key_unique() will work, but only if you refer to fields, and don't try to build more complicated expressions involving other functions.

Here's an example which is patterned after your situation, except the fields of interest are of Character type, instead of Numeric type.

-- tom

[BDennis]

RE: How to avoid duplicate entries to a simple tab

Tom,
Thanks for your help. I think I can figure a way around the problem using your example.
Thanks a lot. You have certainly saved me a lot of time, just by making me realise what a complication the question was in the first place.
Thanks a lot, as always.

Brian