給資料庫去計算公式，CalculateStr可放入一串計算式，db要放入宣告的上例的資料庫連線類別。
建立資料庫連線類別
Imports System.Data
Imports System.Data.SqlClient
Imports Microsoft.ApplicationBlocks.Data
Public Class DataHelper
Private _connString As String = Nothing
#Region "Constructors"
Sub New()
ConnectionString = "ConnectionString"
End Sub
Sub New(ByVal ConnStrName As String)
ConnectionString = ConnStrName
End Sub
#End Region
#Region "Properties"
Public Property ConnectionString() As String
Get
If _connString = "" Then
_connString = ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString
End If
Return _connString
End Get
Set(ByVal value As String)
_connString = ConfigurationManager.ConnectionStrings(value).ConnectionString
End Set
End Property
#End Region
#Region "Common Methods"
' 判斷輸入值是否為空
Public Function GetNull(ByVal Field As Object) As Object
If Not Field Is Nothing Then
If Field.GetType().ToString = "System.String" Then
If Field.ToString = "" Then Return DBNull.Value
End If
Return Field
Else
Return DBNull.Value
End If
End Function
Public Function Checkqstr(ByVal str As String) As String
str = str.Replace("'", "''")
str = str.Replace("%", "")
Return str
End Function
Public Function ExecuteReader(ByVal sqlCmd As String) As IDataReader
Return CType(SqlHelper.ExecuteReader(ConnectionString, CommandType.Text, sqlCmd), IDataReader)
End Function
#End Region
End Class
給資料庫去計算公式，CalculateStr可放入一串計算式，db要放入宣告的上例的資料庫連線類別。
Public Function SelectDbCalculate(ByVal db As DataHelper, ByVal CalculateStr As String) As Single
Try
Dim dr As SqlClient.SqlDataReader = db.ExecuteReader("select " & CalculateStr & "as ANS")
Do While dr.Read
Return dr("ANS")
Loop
Catch ex As Exception
Return 0
End Try
End Function
