Question

我尝试在单个函数中执行两个相关的sql命令，通过一个新的xamlfile更新我的列xamlfile - ＆gt; û

这是我的代码

Public Shared Function updatetest()

    Dim c As SqlConnection = openConnection("Data Source=GENIOP40;Initial Catalog=TF5100_new;Integrated Security=true")
    Dim c2 As SqlConnection = openConnection("Data Source=GENIOP40;Initial Catalog=TF5100_new;Integrated Security=true")
    Dim cmd As New SqlCommand("SELECT xamlfile, id_wkfw_task from WKFW_Tasks Where xamlfile like '%ExecuteTask%' order by name", c)
    Dim rd As SqlDataReader = executereader(cmd)
    Dim listxaml As New List(Of String)
    While rd.Read
        Dim u As String = GetString(rd, "xamlfile")
        Dim Id As Guid = GetGuid(rd, "id_wkfw_task")

        u = Regex.Replace(u, "(?<=<t[1-2]|:ExecuteTask[^><]+)\bTache", "TaskID")

        u = u.Replace("'", "''")

        Dim cmd2 As New SqlCommand("UPDATE WKFW_Tasks set xamlfile=@xmlfile where id_wkfw_task=@id_t", c2)
        cmd2.Parameters.Add("xmlfile", SqlDbType.NVarChar).Value = u
        cmd2.Parameters.Add("id_t", SqlDbType.UniqueIdentifier).Value = Id
        cmd2.CommandTimeout = 0
        executeNonQuery(cmd2)
        c2.Close()

    End While
    rd.Close()
    c.Close()


End Function

我的问题是：当我在循环后关闭阅读器时，我的第一个命令不再被执行，我需要它被执行所以我的第二个命令可以工作，如果我不关闭我的读者我有错误，有什么建议吗？

Answer 1

将初始连接字符串更改为

Dim c As SqlConnection = openConnection("Data Source=GENIOP40;
         Initial Catalog=TF5100_new;Integrated Security=true;
         MultipleActiveResultSets=true")

See MSDN on MultipleActiveResultSets
现在，您不再需要在调用之间关闭DataReader，您可以使用唯一的连接执行命令。但是我建议在循环外部创建update命令及其参数。在循环内部只需更新参数值并执行

Dim cmd2 As New SqlCommand("UPDATE WKFW_Tasks set xamlfile=@xmlfile where id_wkfw_task=@id_t", c)
cmd2.Parameters.Add("xmlfile", SqlDbType.NVarChar)
cmd2.Parameters.Add("id_t", SqlDbType.UniqueIdentifier)
While rd.Read
    ....

    cmd2.Parameters("xmlfile")..Value = u
    cmd2.Parameters("id_t").Value = Id
    executenonquery(cmd2)
 End While

执行VB.NET中相关的两个sql命令

1 个答案: