如何解决“必须声明标量变量@cds”sql？

Question

最近三个小时。我搜索了互联网寻找解决问题的方法。我发现了一些，但他们都没有工作（！？）。错误在btnAdd Sub中。我无法使用这种形式的声明：'DECLARE @cds SqlDBType.SmallInt，因为我会得到以下错误：语句在方法/多行lambda中无效。我还使用了他们的声明http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqldataadapter.insertcommand%28v=vs.110%29.aspx的形式，但是我又收到了同样的错误。评论部分是我尝试的一切。也许你可以帮我解决这个问题。 :)

更新正确的解决方案：

Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click 

    con.Open() 

    Dim dr As DataRow 

    mycmd.CommandText = "insert into studenti(cods, nrmatricol, nume, grupa, datan) values(@cs,@nm,@n,@g,@dn)" 

    Dim p1 As New SqlParameter 
    Dim p2 As New SqlParameter 
    Dim p3 As New SqlParameter 
    Dim p4 As New SqlParameter 
    Dim p5 As New SqlParameter 

    mycmd.Parameters.Clear() 

    p1.ParameterName = "@cs" 
    p1.Value = Convert.ToInt16(txtCodS.Text) 
    mycmd.Parameters.Add(p1) 

    p2.ParameterName = "@nm" 
    p2.Value = txtNrMat.Text 
    mycmd.Parameters.Add(p2) 

    p3.ParameterName = "@n" 
    p3.Value = txtNume.Text 
    mycmd.Parameters.Add(p3) 

    p4.ParameterName = "@g" 
    p4.Value = txtGrupa.Text 
    mycmd.Parameters.Add(p4) 

    p5.ParameterName = "@dn" 
    p5.Value = Convert.ToDateTime(txtDataN.Text) 
    mycmd.Parameters.Add(p5) 

    mycmd.Connection = con 
    da1.InsertCommand = mycmd 

    dr = DataSet1.Tables("studenti").NewRow() 

    dr("cods") = Convert.ToInt16(txtCodS.Text) 
    dr("nrmatricol") = txtNrMat.Text 
    dr("nume") = txtNume.Text 
    dr("grupa") = txtGrupa.Text 
    dr("datan") = Convert.ToDateTime(txtDataN.Text) 

    DataSet1.Tables("studenti").Rows.Add(dr) 

    da1.Update(DataSet1, "studenti") 

    UpdateUI() 


    con.Close() 


End Sub 

错：

Dim da1 As New SqlClient.SqlDataAdapter 

    Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click 

     con.Open() 

     Dim dr As DataRow 
     Dim mycmd As New SqlClient.SqlCommand 
     //Dim mycmd2 As New SqlClient.SqlCommand 

     //mycmd2.Connection = con 
     //  mycmd2.CommandText = "select* from studenti" 


     //Dim v(4) As Object 


     //v(0) = Convert.ToInt16(txtCodS.Text) 
     //v(1) = txtNrMat.Text 
     //v(2) = txtNume.Text 
     //v(3) = txtGrupa.Text 
     //  v(4) = txtDataN.Text 

     mycmd.CommandText = "insert into studenti (cods,nrmatricol,nume,grupa,datan) values (@cds,@nm,@n,@g,@dn)" 

     Dim p1 As New SqlClient.SqlParameter 
     p1.ParameterName = "@cds" 
     p1.Value = Convert.ToInt16(txtCodS.Text) 


     //DECLARE @cds SqlDBType.SmallInt 
     //cmd.Parameters.Clear() 

     cmd.Parameters.Add(p1) 
     //cmd.Parameters.Add("@cds", SqlDbType.SmallInt).Value = Convert.ToInt16(txtCodS.Text) 
     cmd.Parameters.Add("@nm", SqlDbType.VarChar, 10) 
     cmd.Parameters.Add("@n", SqlDbType.VarChar, 30) 
     cmd.Parameters.Add("@g", SqlDbType.VarChar, 10) 
     cmd.Parameters.Add("@dn", SqlDbType.DateTime) 

     mycmd.Connection = con 
     da1.InsertCommand = mycmd 

     dr = DataSet1.Tables("studenti").NewRow() 

     dr("cods") = Convert.ToInt16(txtCodS.Text) 
     dr("nrmatricol") = txtNrMat.Text 
     dr("nume") = txtNume.Text 
     dr("grupa") = txtGrupa.Text 
     dr("datan") = Convert.ToDateTime(txtDataN.Text) 


     DataSet1.Tables("studenti").Rows.Add(dr) 

     da1.Update(DataSet1, "studenti") 

     UpdateUI() 

     con.Close() 

    End Sub 
End Class 

Answer 1

@cds变量由它是由cmd.Parameters.Clear()除去后进行设置。 只需删除这行代码并为@cds提供一个值。