vb.net - 使用带有标量查询的语句

Question

你能展示一个带有标量查询的“Using”语句的编码示例吗？

我无法通过搜索找到任何示例编码。

Answer 1

以下是 MSDN 页面上有关 ExecuteScalar 方法的示例：

Public Function AddProductCategory(ByVal newName As String, ByVal connString As String) As Integer
    Dim newProdID As Int32 = 0
    Dim sql As String = _
     "INSERT INTO Production.ProductCategory (Name) VALUES (@Name); SELECT CAST(scope_identity() AS int);"

    Using conn As New SqlConnection(connString)
        Dim cmd As New SqlCommand(sql, conn)
        cmd.Parameters.Add("@Name", SqlDbType.VarChar)
        cmd.Parameters("@Name").Value = newName
        Try
            conn.Open()
            newProdID = Convert.ToInt32(cmd.ExecuteScalar())
        Catch ex As Exception
            Console.WriteLine(ex.Message)
        End Try
    End Using

    Return newProdID
End Function

这是链接：

http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.executescalar.aspx#Y374