带参数的更新命令不会更新数据表

Question

The whole night I've tried many ways BUT sql Update command with parameters is not updating data table. I am totally fade up. The execution is successful and returns 1 row affected BUT old data is not being replaced. Please help me out.

conn.Open();
string updateSql = "UPDATE tbl_cust SET fname=@fname, lname=@lname WHERE email=@email";  
SqlCommand UpdateCmd = new SqlCommand(updateSql, conn);

UpdateCmd.Parameters.Add("@fname", SqlDbType.NVarChar, 50, "fname");
UpdateCmd.Parameters.Add("@lname", SqlDbType.NVarChar, 50, "lname");
UpdateCmd.Parameters.Add("@email", SqlDbType.NVarChar, 50, "email");

UpdateCmd.Parameters["@fname"].Value = txtFirstName.Text;
UpdateCmd.Parameters["@lname"].Value = txtLastName.Text;
UpdateCmd.Parameters["@email"].Value = Session["sesEmail"].ToString();         
UpdateCmd.ExecuteNonQuery(); 

---

Another method: (same result)

SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["Hib"].ConnectionString);
string upData = "UPDATE tbl_cust SET fname=@fname, lname=@lname, addrs=@address WHERE email=@email";

SqlCommand cmd = new SqlCommand(upData, conn);
conn.Open();

cmd.Parameters.AddWithValue("@fname", fName);
cmd.Parameters.AddWithValue("@lname", lName);
cmd.Parameters.AddWithValue("@addrs", address);
cmd.Parameters.AddWithValue("@email", Session["sesEmail"].ToString());

int n = cmd.ExecuteNonQuery();
Response.Write("<script>alert('rows affected = " + n + "');</script>");
Response.Write("<script>alert('sesEmail = " + Session["sesEmail"].ToString() + "');</script>");

Answer 1

I would debug this by creating a stored procedure that accepts the parameters, then I would run the procedure manually from SSMS (SQL Server Management Studio). Confirm that the procedure itself, given the correct parameters, works, then call the procedure instead of inline SQL from the front end (this is a better approach anyway).

IE

CREATE PROCEDURE usp_UpdateCustTable
@fname varchar(50),
@lname varchar (50),
@email varchar(50) 

AS

--EXEC usp_UpdateCustTable 'Joe', 'Blow', 'joe.blow@acmecompany.com'


UPDATE tbl_cust SET fname=@fname, lname=@lname WHERE email=@email

After you create the proc, run the commented out EXEC portion of the sample. Once you know the procedure is working, the issue can only boil down to the Session variable being empty, invalid connect string, or some related issues. Have you set a break point and monitored the code?

Let me know; I feel your pain, :-)

Answer 2

And the magic is...Problem solved. Thank you, everyone. You are all very helpful. It was my very first post here and I'm so happy to see the prompt response from the expert panel. Thanks again.

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