Link to home
Start Free TrialLog in
Avatar of jzlamal
jzlamalFlag for United States of America

asked on

Button to update row in gridview

I am new to asp.net and I am hoping you can help with a question on gridview controls.   I have a gridview control that shows a list of transactions.   I have added two buttons (Approve/Rescind) to the gridview that I would like to update a field on the record.   There is a SQL data source that is attached to the gridview control and I have created two separate SQL data sources with the appropriate update statements for the updating the field.  I have assigned the buttons with CommandName attributes of "Approve" and "Rescind" respectively.   A couple of questions...

1.  There is a transaction ID in the select statement used by the gridview.   It is the primary key for the table and I would need to use this for my update statement.  How do I get the transaction id associated with the buttons on a given row?  

2.  How would I initiate the update (assume this is done in the C# code)?

Thank you!
John
Avatar of BuggyCoder
BuggyCoder
Flag of India image

Avatar of Tom Beck
How do I get the transaction id associated with the buttons on a given row?  

Add a CommandArgument attribute to the button to hold the transaction ID.

<asp:Button ID="btnTest" Text="Approve" runat="server" CommandName="Approve" CommandArgument='<%# Bind("transactionid") %>' OnCommand="btnTest_Command" />

Handle the update on the button click, retrieve the transaction id from the CommandArgument.
protected void btnTest_Command(object sender, CommandEventArgs e)
        {
            if (e.CommandName == "Approve")
            {
                string transactionId = (string)e.CommandArgument;
                //Update the database
            }
        }

Open in new window

Avatar of jzlamal

ASKER

I tried your suggestion and I received the following...

System.Web.UI.WebControls.DataControlFieldCollection must have items of type 'System.Web.UI.WebControls.DataControlField'. 'asp:Button' is of type 'System.Web.UI.WebControls.Button'

Is the Button field you provided appropriate for adding inside a gridview control or do I need to use something else?

Thanks!
john
ASKER CERTIFIED SOLUTION
Avatar of Tom Beck
Tom Beck
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of jzlamal

ASKER

Ok.  So the transaction ID is being passed when I click on the button.   However, it is not being passed along to the update statement.   In the btnTest_Command, I am calling the Update method of the SQL Datasource using "UpdApprove.Update()".   I have a SQL Data source defined as:

<asp:SqlDataSource ID="UpdApprove" runat="server"
        ConnectionString="<%$ ConnectionStrings:PMMARTConnectionString %>"
        UpdateCommand="UPDATE [TT_TRANS] SET [ApprovedFlag] = 'Y', [ApprDate] = getdate() WHERE [TranID] = @TranID">
        <UpdateParameters>
            <asp:Parameter Name="TranID" Type="String" />
        </UpdateParameters>
    </asp:SqlDataSource>

Do I need to do anything else to pass the transactionID from the btnTest_Command to the SQLDataSource?   Even though the button is getting the correct transaction id, it doesn't seem to be passing it along to the update statement.  Thanks!
Avatar of jzlamal

ASKER

Once I added a line to update the UpdateParameter, everything worked.   Thank you so much!
You are revealing new circumstances that were not part of your original question. The method I presented assumed that you were manually updating your database. If you are using all the built-in mechanisms for populating/updating a Gridview then disregard my suggestion. There are multiple ways to do this. You could specify an OnRowUpdating event in your GridView markup.

<asp:GridView ID="GridView1" OnRowUpdating="GridView1_RowUpdating"....

You could add DataKeyNames to get the transaction ids.

...DataKeyNames="transactionid" >

Then in the <columns> block you could include a command field.

<asp:CommandField ShowDeleteButton="True" ShowEditButton="True" />

When a user clicks the Edit link, in code behind, switch to Update mode.
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
        {
            GridView1.EditIndex = e.NewEditIndex; // turn to edit mode
            BindGridView(); // Rebind GridView to show the data in edit mode
        }

Open in new window


This should change your BoundFields to textboxes and the Edit/Delete link to Update/Cancel.

User makes changes and clicks Update link

Then in the RowUpdating event.
protected void gridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
        {
             string transactionId = (string)GridView1.DataKeys[0].Value;
             //Use the DataKey as the Update statement parameter
        }

Open in new window


But, like I said, there are many possibilities.
Our posts crossed. Thanks for the points. Glad to help.