Paradox Table: how to avoid key violation 1

[guava65]

I'm trying to input data to a paradox table with three (3) fields: ID, Date, Comment. the only key is the ID field.

When I enter a duplicate ID. I get a "key violation" error. :-V How do I avaoid this? I do not want the key field to be unique. :-V Is there a special way to handle this with a paradox table? I have no problems with dBase tables.

Thank you in advance.

cg

Mahalo,
cg

 

[TealWren]

You could add an autoinc key field. Make that field your primary key. Paradox will automatically put a new number in that field every time you add a record, and then you shouldn't have to worry about it.

Good luck!
TealWren

 

[svanels]

The AutoInc Field will work in a single user environment, if there is a possibility that more then one user or application will access the database, it should be avoided.
A work around is described below

Ok first you have to create a counter table which stores the next ID number(1 record, 1 field).

inserting a new record;

a) Open the counter table
b) Retrieve the number
c) Increase the counter
d) Close the counter table;

Create your CounterTable
NextRecord --> integer;
fill in your starting value (100);

Create your main table, (Main_table) where your ID_field is an integer key field

On Newrecord event handler:

procedure Main_TableNewRecord(DataSet: TDataSet);
begin
with COUNTERTABLE do
begin
Open;
try
edit;
Main_TableIDfield.Value := NEXTRECORD.Value; // retrieve number
NEXTREC.Value := NEXTREC.Value + 1; // update counter
Post; //close the Counter table
finally
Close;
end;
end;
end;


Regards S. van Els
SAvanEls@cq-link.sr

 

[guava65]

Thanks.

This is similar to what I have done in the past to generate purchase order and invoice numbers. I'll use this technique in this case as well.

cg Mahalo,
cg