使用C＃将外键插入表中

Question

I hope you don't mind if I ask for your opinions about how to insert a foreign key into a table without running a couple of queries.

I have made a sample UI and a sample table just to illustrate my situation.

Here's what I usually do when inserting, first I do a query against the database and loads the result into the ComboBox. After that I run a query again to get the Id of the selectedItem on the comboBox before doing the INSERT or UPDATE query, but it feels like there is a much better solution without hitting the database too much.

Any idea will be greatly appreciated.

Regards.

Answer 1

When loading the items into the ComboBox you could use a dataset, say like retrieved from this

"SELECT Id, NameColumn FROM sampleTable"

Then you can set the ComboBox DisplayMember and ValueMember attributes like so

combobox1.ValueMember = "Id";
combobox1.DisplayMember = "NameColumn";

That way, when you try to retrieve the Id of the item all you need to do is something like

var item = combobox1.SelectedValue;

You only need to hit the database now to load the items into the ComboBox in the first place, before your INSERT or UPDATE .