CODEWITHSUNDEEP
c#mysqldatabasetextboxsql-insert
Paolo Duhaylungsod
Paolo Duhaylungsod

Reputation: 487

value from database not visible in textbox and insert value to the right username

As of now here is my code:

protected void Button2_Click(object sender, EventArgs e)
        {
            using (SqlConnection scn = new SqlConnection("Data Source = 'PAULO'; Initial Catalog=ShoppingCartDB;Integrated Security =True"))
            {
                scn.Open();
                SqlCommand cmd = new SqlCommand(@"UPDATE UserData SET CreditRequest =
                     CAST(REPLACE(CreditRequest, ',', '') as int) 
                     FROM CreditRequests Where Username=@Username;
                     SELECT CreditRequest FROM UserData 
                     WHERE Username=@Username", scn);
                cmd.Parameters.Add("@Username", SqlDbType.NVarChar).Value = Session["New"];

                object value = cmd.ExecuteScalar();

                if (value != null)
                    txtCredit.Text = value.ToString();
            }
            }
        }

However, when i look at my database, the credit request value is being inserted to the database and makes new ID's and everything is NULL.

Example

ID NULL Username NULL Email NULL Contact NULL Creditrequest 5,000

Is there a way to insert the credit request value to the right username. What am i missing in my code?

Also, i want that credit request value to be shown in my textbox and i believe its this line of code?

if (value != null)
    txtCredit.Text = value.ToString();

Upvotes: 0

Views: 77

Answers (1)

Steve
Steve

Reputation: 216293

You are calling an INSERT statement that adds a new record. And no, adding a WHERE clause at the end, doesn't transform an insert statement in an update statement.

If you want to UPDATE an existing record then you call 

 SqlCommand cmd = new SqlCommand(@"UPDATE UserData SET CreditRequest =
                     (SELECT CAST(REPLACE(c.CreditRequest, ',', '') as int) 
                     FROM CreditRequests c Where c.Username=@Username)", scn);

For the second part of your question, is not possible to get the return value of ExecuteScalar in this context because UPDATE doesn't select any record to return. If you want to get back that value you could issue two statement together separating them with a semicolon:

 SqlCommand cmd = new SqlCommand(@"UPDATE UserData SET CreditRequest =
                     (SELECT CAST(REPLACE(c.CreditRequest, ',', '') as int) 
                     FROM CreditRequests c Where c.Username=@Username);
                     SELECT CreditRequest FROM UserData u
                     WHERE u.Username=@Username", scn);

Both statements will be executed, but ExecuteScalar will be able to return the CreditRequest updated

Upvotes: 1

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