C# Update SQL语句未触发到数据库

我想知道我的代码中遗漏了什么。我只想从

creditrequest

表中获取一个特定值，

creditrequest

，并将其放入

UserData

表的

creditrequest

列中。不知何故，我的代码没有执行任务

这是我的密码：

using (SqlConnection scn = new SqlConnection("Data Source = 'PAULO'; Initial Catalog=ShoppingCartDB;Integrated Security =True"))
{
    scn.Open();

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

    cmd.Parameters.Add("@Username", SqlDbType.NVarChar).Value = Session["New"];

    cmd.ExecuteNonQuery();
}

---

让我们逐行查看代码

using (SqlConnection scn = new SqlConnection("Data Source = 'PAULO'; Initial Catalog=ShoppingCartDB;Integrated Security =True"))
//I hope this is correct. Else "Server=PAOLO;Database=ShoppingCartDB;Integrated Security=True"
{
    scn.Open();
/*
    SqlCommand cmd = new SqlCommand(@"UPDATE UserData SET CreditRequest = 
    (SELECT CAST(REPLACE(c.CreditRequest, ',', '') as int) 
    FROM CreditRequests c Where c.Username=@Username", scn);
*/
    //SQL statement is all wrong and can update all rows
    //Correct is
    SqlCommand cmd = new SqlCommand(@"UPDATE UserData SET CreditRequest = "
        + "CAST(REPLACE(c.CreditRequest, ',', '') as int) "
        + " FROM CreditRequests c inner join UserData u "
        + "on c.Username=u.Username Where c.Username=@Username", scn);
    cmd.Parameters.Add("@Username", SqlDbType.NVarChar).Value = (string)Session["New"]; //This is good

    cmd.ExecuteNonQuery();
}

---

为什么你有两种说法。请尝试删除下一条

选择

，然后改用

ExecuteOnQuery

。尝试删除第二条语句（忘记删除），并将其更改为ExecuteOnQuery。@FelixPamittanfyi仍然不起作用，我的另一个按钮中有相同的代码，工作非常好。不知道为什么这个不起作用，参数的结构就是这样。Cmd.paramaters.add（新的sqlparamater（@Username），传递的值））；正如@felix提到的，使用cmd.executenonquery，因为不会返回任何结果。谢谢@Shon。已使用ExecuteOnQuery，但仍然没有给出结果。