c# - Unable to find error while inserting data into database

Question

Can some one here tell me what is wrong with my code? Benn spending like an endless hour finding the error.

 protected void Button1_Click(object sender, EventArgs e)
{
    SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["Connection"].ConnectionString);
    SqlCommand cmd = new SqlCommand("Insert into CarReserve(UserName,Manufacture,Model,Plate,DateReturn,TimeReturn) Values (@Username1,@Manufacture1,@Model1,@Plate1,@Date1,@TimeReturn1)", conn);

    cmd.CommandType = CommandType.Text;
    cmd.Parameters.AddWithValue("@Username1", Label1.Text);
    cmd.Parameters.AddWithValue("@Manufacture1", Label3.Text);
    cmd.Parameters.AddWithValue("@Model1", Label4.Text);
    cmd.Parameters.AddWithValue("@Plate1", Label5.Text);
    cmd.Parameters.AddWithValue("@Datel", Label6.Text);
    cmd.Parameters.AddWithValue("@TimeReturnl", Label7.Text);

    conn.Open();
    cmd.ExecuteNonQuery();
    Response.Redirect("HomeUser.aspx"); 

}

The error is must declare the scalar var @Date1. Thanks in advance.

Answer 1

cmd.Parameters.AddWithValue("@Datel", Label6.Text);

看起来您输入@Date**l**的是“字母 ell”而不是@Date**1**“第一”。

看起来您也对以下行犯了同样的错误：

cmd.Parameters.AddWithValue("@TimeReturnl", Label7.Text);

Answer 2

据我所知，您应该将参数及其值放在 sql 查询字符串之前，例如：

SqlConnection conn = new SqlConnection  (ConfigurationManager.ConnectionStrings["Connection"].ConnectionString);
SqlCommand cmd = new SqlCommand(conn);

cmd.Parameters.AddWithValue("@Username1", Label1.Text);
cmd.Parameters.AddWithValue("@Manufacture1", Label3.Text);

cmd.CommandText = "Insert into CarReserve(UserName,Manufacture,Model,Plate,DateReturn,TimeReturn) Values (@Username1,@Manufacture1,@Model1,@Plate1,@Date1,@TimeReturn1)";

cmd.CommandType = CommandType.Text;