<SOLVED> Prevent duplicates conditionally

[MyNameIsSean]

Hi,

I have a relational database set up in a way that I have a Customers table, Products table, and I create entries in the Proposal table, that links the 2 tables together.

I would not like to create a proposal that connects the same customer to the same product twice, however there is one product that is open (id = 16), and is the exception (i can have multiple proposals created for the same customer, to that open product).

I was thinking that I can create a checking field in the Proposal table that is a unique text field, and it will take a concatenate value of the customer Id and the product id to create a unique identifier. However it will not work for the open product, so I was thinking to insert a random number into the checking field such that it will bypass the unique value criteria present in that field.

I currently have this, which the concatenate function works perfectly in generating and inserting the checking value, but the random value inserts "undefined" into the field.

<SCRIPT LANGUAGE="JavaScript">

function concatenate()
{
var identifier1 = document.getElementById("InsertRecordProduct_ID").value;
var identifier2 = document.getElementById("InsertRecordCustomer_ID").value;

var concat_identifier = identifier1 + "P" + identifier2 + "C";

if (identifier1 !== "16") {

document.getElementById("InsertRecordChecker").value = concat_identifier;

} else {

document.getElementById("InsertRecordChecker").value = Math.random().ToString().value;

}
}

document.getElementById("caspioform").onsubmit=concatenate;

</SCRIPT>

 

Is there a problem with my code, or is there a better solution to this problem?

Thanks in advance.

[MyNameIsSean]

I have come up with the following solution:

 

<SCRIPT LANGUAGE="JavaScript">

function concatenate()
{

var identifier1 = document.getElementById("InsertRecordProduct_ID").value;
var identifier2 = document.getElementById("InsertRecordCustomer _ID").value;

var concat_identifier = identifier1 + "P" + identifier2 + "C";

var text = "";
    var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

    for( var i=0; i < 5; i++ )
        text += possible.charAt(Math.floor(Math.random() * possible.length));

if (identifier1 !== "16") {

document.getElementById("EditRecordChecker ").value = concat_identifier ;

} else {

document.getElementById("EditRecordChecker ").value = text;

}
}
document.getElementById("caspioform").onsubmit=concatenate;

</SCRIPT>