Question

任何人都知道在VB.NET中创建和初始化SqlParameter的更好方法吗？每个变量使用3行似乎相当过分。不幸的是，这个类的constructors非常荒谬，所以我只想编写自己的sub来初始化每个参数。这就是我一直在做的事情。

Dim ID As New SqlParameter("@ID", SqlDbType.Int)
ID.Value = val
query.Parameters.Add(ID)

这是我用于完整代码的完整代码，即使是只需要一个参数的简单存储过程。我有一些需要15-20，这是使用这种笨重方法的大量代码。

Dim query As New SqlCommand("spGetInitStatusEntry", connection)
query.CommandType = CommandType.StoredProcedure
Dim ID As New SqlParameter("@ID", SqlDbType.Int)
ID.Value = val
query.Parameters.Add(ID)
Dim dt As New DataTable
Dim da As New SqlDataAdapter(query)
da.Fill(dt)

最终实施

我按照建议使用两个支持Module创建了以下<Extension()>。

Module TcomExtensions
    <System.Runtime.CompilerServices.Extension()> _
    Public Sub AddParameter(ByRef dbCommand As SqlCommand, ByVal parameterName As String, _
            ByVal parameterValue As Object, ByVal dbType As SqlDbType)

        Dim dbParameter As SqlParameter = Nothing
        dbParameter = dbCommand.CreateParameter

        dbParameter.ParameterName = parameterName
        dbParameter.Value = parameterValue
        dbParameter.DbType = dbType

        dbCommand.Parameters.Add(dbParameter)
    End Sub

    <System.Runtime.CompilerServices.Extension()> _
    Public Function ToDataTable(ByVal value As SqlCommand) As DataTable
        Dim dt As New DataTable
        Using da As New SqlDataAdapter(value)
            da.Fill(dt)
        End Using
        Return dt
    End Function
End Module

我的实施如下：

Dim spPrefill As New SqlCommand("spGetPrefillStatusEntry", connection) With {.CommandType = CommandType.StoredProcedure}
'Only one line per added parameter.
spPrefill.AddParameter("@ID", val, SqlDbType.Int)
'Populate the table.
dt = spPrefill.ToDataTable()

Answer 1

您还可以合并前两行：

Dim query As New SqlCommand("spGetInitStatusEntry", connection) With {.CommandType = CommandType.StoreProcedure}

扩展方法也可以在这里成为你的朋友：

<Extension()> _
Public Function ToDataTable(ByVal value As SqlCommand) As DataTable
  Dim dt As New DataTable
  Using da As New SqlDataAdapter(value)
    da.Fill(dt)
  End Using
  Return dt
End Function

除了Mike Hofer对AddWithValue的建议外，现在可以将其简化为：

Dim query As New SqlCommand("spGetInitStatusEntry", connection) With {.CommandType = CommandType.StoreProcedure}
query.Parameters.AddWithValue("@ID", key)
Dim dt As DataTable = query.ToDataTable();

如果使用AddWithValue不舒服，您也可以将参数信息写在一行中：

query.Parameters.Add(New SqlParameter("@ID", SqlDbType.Int) With {.Value = key})

Answer 2

有了这些扩展...

 <System.Runtime.CompilerServices.Extension()> _
Public Sub AddParameterValue(ByRef dbCommand As System.Data.Common.DbCommand, ByVal parameterName As String, ByVal parameterValue As Object)
    dbCommand.AddParameter(parameterName, parameterValue)
End Sub


<System.Runtime.CompilerServices.Extension()> _
Public Sub AddParameter(ByRef dbCommand As System.Data.Common.DbCommand, ByVal parameterName As String, Optional ByVal parameterValue As Object = Nothing, Optional ByVal sourceColumn As String = "")
    Dim dbParameter As System.Data.Common.DbParameter = Nothing


    dbParameter = dbCommand.CreateParameter

    dbParameter.ParameterName = parameterName
    dbParameter.Value = parameterValue
    dbParameter.SourceColumn = sourceColumn

    dbCommand.Parameters.Add(dbParameter)

End Sub

...您将能够使用1行代码添加参数

Dim query As New SqlCommand("spGetInitStatusEntry", connection)
query.CommandType = CommandType.StoredProcedure
query.AddParameterValue("@ID", key)
Dim dt As New DataTable
Dim da As New SqlDataAdapter(query)
da.Fill(dt)

该函数非常通用，未指定参数类型，但如果确实需要，可以将其添加为参数。

Answer 3

query.AddWithValue（“@ ID”，key）

有没有更好的方法在VB中使用SqlParameters调用存储过程？

最终实施

3 个答案: