CODEWITHSUNDEEP
c#sql-server
Dave Faundo
Dave Faundo

Reputation: 13

Updating information in SQL via C# Visual Studio does not work

I have created a program (for school) that has create account, manage account (update and delete), and delete account. All functions work except for Update and I am not sure why. There's no error whatsoever, it just does nothing. Below is the code:

    private void btnUpdate_Click(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["myCon"].ConnectionString);
        con.Open();
        using (SqlCommand cmd = new SqlCommand("UPDATE Inventory SET ItemID=@ItemID, ItemName=@ItemName, ItemType=@ItemType, Quantity=@Quantity,WarehouseLocation=@WarehouseLocation,QuadrantNumber=@QuadrantNumber,BinNumber=@BinNumber,DateUpdated=@DateUpdated" +
                " WHERE ItemID= '" + txtItemID.Text + "'", con))
        {
            if (txtItemID.Text == "@ItemID")
            {
                cmd.Parameters.AddWithValue("@ItemName", txtItemName.Text);
                cmd.Parameters.AddWithValue("@ItemType", cmbType.Text);
                cmd.Parameters.AddWithValue("@Quantity", udQuantity.Text);
                cmd.Parameters.AddWithValue("@WarehouseLocation", cmbWarehouse.Text);
                cmd.Parameters.AddWithValue("@QuadrantNumber", cmbQuadrant.Text);
                cmd.Parameters.AddWithValue("@BinNumber", cmbBin.Text);
                cmd.Parameters.AddWithValue("@DateUpdated", Convert.ToString(DateTime.Now));
                cmd.ExecuteNonQuery();
                con.Close();

                MessageBox.Show("Item Updated!");
            }
        }
    }

Upvotes: 1

Views: 52

Answers (1)

RKrum
RKrum

Reputation: 410

This answer is based in assumption you already have this item in your DB and you just need to update it. I'll separate the answer in three steps:

First step: I assume your primary_key is the ItemID, so you shouldn't really update it as you're doing here:

UPDATE Inventory SET ItemID=@ItemID,...

You should just remove the ItemID = @ItemID, part, as we don't want to update it.

Second step: Now, this piece of code looks incorrect:

if (txtItemID.Text == "@ItemID")

It will try to match the txtItemID.Text with the string "@ItemID", which I believe it is not your goal, since I can understand it is your ID - It would be always false.

You should just remove this if.

Third step: You also need to change your where clause to have your ItemID as parameter, as below:

" WHERE ItemID=@ItemID", con))

Then add it to your parameters:

cmd.Parameters.AddWithValue("@ItemID", txtItemID.Text);

You should be good with these changes.

Another thing you could do is to always debug your application when you're struggling to understand a problem. It helps a lot!

Upvotes: 1

Related Questions