Question about UPDATE command in VB.NET

[rahavtom]

Hello !

 

My question is this:

I add record to dataset using .AddNew command. Then I update this record with 'Begin Edit' and 'End Edit' commands, and finally I want to 'save' this record to the database (mdb file) using UPDATE command.

When I do this, and in case that record with the same values (in key fields) is already exist in the database, I get an error message that the operation can't be done because it will create a duplicate key and so on.... before I perform the UPDATE command, I update the data adapter SELECT, UPDATE and DELETE commands with GetUpdateCommand, etc.

How can I 'tell' the UPDATE command to perform an UPDATE action when record already exist, and to INSERET a new record when it doesn't ?

 

Hope it's clear enough...

Thanks,

Tom.

[Robby]

An Update cmd needs a Where clause, in a sense you need to pin-point the exact record to update, Is this what you are currently doing?

 

If the record already exists, is this not what you want? To update an existing record.

[rahavtom]

An Update cmd needs a Where clause, in a sense you need to pin-point the exact record to update, Is this what you are currently doing?

 

If the record already exists, is this not what you want? To update an existing record.

 

When I create the dataset I use a WHERE condition, so the dataset contains only the records I want.

After I declare it, I use the following syntax to get the UPDATE command automatically from the DB:

 

DataAdapter.UpdateCommand = CommandBuilder.GetUpdateCommand

 

Then, when I update the dataset into the database, I use:

 

DataAdapter.Update(DataSet, "TableName")

 

What should I do ?

 

Thanks,

Tom.