Help me with my parent\Child tables issue

Question

0.00/5 (No votes)

See more:

Hello Guys
In my windows application project I am using Dataset. There are three tables:

Product
---------------
Title, ID, Price

Invoice
---------------
ID, Date, Description

InvoiceItem
---------------
ID, Product_ID, Invoice_ID, Quantity

All ID columnns are Identity and tablename_ID format columns are foreign Keys.

In a single form named BuyForm I get all inputs and then in a Save_ButtonCLick I want to Insert these information to the related tables I have mentioned.
After some googling I found this article:
Inserting relational data using DataSet and DataAdapter
Here is my code according to what I understand from that article:

C#

DataRow invoice = DataSet.Tables["Invoice"].NewRow();
        invoice["Date"] = DateConverter.ToPersianDate();
        invoice["Description"] = string.Empty;
        DataSet.Tables["Invoice"].Rows.Add(invoice);
                    
        DataRow product = null;
        DataRow invoiceItem = null;
        foreach (DataGridViewRow row in ProductGridView.Rows)
        {
            product = DataSet.Tables["Product"].NewRow();
            invoiceItem = DataSet.Tables["InvoiceItem"].NewRow();
        
            product["Title"] = row.Cells["ProductColumn"].Value.ToString();
            product["BuyPrice"] = row.Cells["BuyPriceColumn"].Value;
            product["SellPrice"] = row.Cells["SellPriceColumn"].Value;
            invoiceItem["Count"] = row.Cells["CountColumn"].Value;
        
            invoiceItem.SetParentRow(invoice);
            product.SetParentRow(invoice);
            DataSet.Tables["Product"].Rows.Add(product);
            DataSet.Tables["InvoicItem"].Rows.Add(invoiceItem);
        
            TableAdapterManager.UpdateAll(DataSet);              
         }

This error occurs at time of adding invoiceItem to its DataTable:

Column 'Product_ID' does not allow nulls.

How should I change my code?
Thanks

Posted 30-Jul-15 10:08am

Meysam Toluie

Updated 30-Jul-15 10:11am

v3

Add a Solution

Comments

[no name] 30-Jul-15 16:31pm

Either set a value for Product_ID or change the database to allow null values for that column.

Meysam Toluie 30-Jul-15 21:08pm

the ID columns is Identity and I am using disconnected architecture. did you see?

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Wendelius · Answer 1 · 2015-08-01T02:05:00

You don't specify the Product_Id for an InvoiceItem and that causes the problem. The Identity fields are used only for primary keys and based on you description, Product_ID is a foreign key so you must define the value for it, one way or another. So probably you should have

C#

invoiceItem.SetParentRow(product);

As a side-note the row

C#

product.SetParentRow(invoice);

looks odd since I doubt that invoice is a parent of product.