Combox that contains letters textboxs stop working

Question

I'm working with Form 1 I have 15 textboxes and 2 combo boxes. You can select from the combo box exp: 123, 456 B789. Program works well as long as I dont select B789 has a letter in it. I can change it to 123 or 456 and i can add to any textbox. The Letter has stumped me.

 

In the beginning my dbo.Table was set to Numric for the combobox I have changed it to Varchar but it still dont work.

 

If I try to add to any other textbox with a letter in the combobox  it stops.

 

what else should I be looking at?

 

Answer 1

Look at the Sam's Post to learn basics of ADO etc.

Read this post, it will full-fil your ask. here you will find a working example too.

http://www.c-sharpcorner.com/UploadFile/abhikumarvatsa/1605/

Answer 2

Look at the following. I know that the Forms section is quite large, but you will see the abundance of useful material.

• ADO.NET in C#
• Windows Forms in C#