提交表单C＃之后，从数据库中检索最新的主键

Question

I have a Webforms project and I have the information going into a database. My question is, after submitting the page, how can I retrieve and display the newly created ID (primary key) on the next page in a label? Is this even possible to do?

I have this code for retrieving the ID based of an old project I did:

SqlCommand da3 = new SqlCommand(strSelectCmd3, conn);
da3.CommandType = CommandType.StoredProcedure;

SqlDataAdapter ds3 = new SqlDataAdapter();
ds3.SelectCommand = da3;

DataSet dsPerson3 = new DataSet();
ds3.Fill(dsPerson3);

Response.Redirect("Submitted.aspx?ID=" + dsPerson3.Tables[0].Rows[0]["CremationID"].ToString());

Answer 1

In your insert SQL stored procedure, either SELECT the SCOPE_IDENTITY() directly, or set an output variable to that. This will give you the PK for this table.

You can then use that id as a part of the query string for the next page. This will allow you to load that page without needing to make a separate call to the database, and you will be guaranteed to have the correct id.

Trying to figure out the last id without using something scope-specific like this (such as SCOPE_IDENTITY), will have the issue that you might receive an Id inserted by another process / user on the page, rather than the one just handled.

Answer 2

I added this statement inside of my stored procedure:

SELECT TOP (1) CremationID, Last, First
FROM dbo.Cremation
WHERE (Last = @Last) AND (First = @First)
ORDER BY CremationID DESC

And then on the new pages inserted a label and put this code inside of the Page_Load

CID.Text = Request.QueryString["ID"].ToString();