ado|对象
n Overloads Public Overridable Function Add(ByVal value As Object) As Integer Implements IList.Add
n Overloads Public Function Add(ByVal parameterName As String,ByVal value As Object) As OleDbParameter
n Overloads Public Function Add(ByVal value As OleDbParameter) As OleDbParameter
n Overloads Public Function Add(ByVal parameterName As String,ByVal oleDbType As OleDbType) As OleDbParameter
n Overloads Public Function Add(ByVal parameterName As String,ByVal oleDbType As OleDbType,ByVal size As Integer) As OleDbParameter
n Overloads Public Function Add(ByVal parameterName As String,ByVal oleDbType As OleDbType,ByVal size As Integer,ByVal sourceColumn As String) As OleDbParameter
示例
Public Sub CreateOleDbParamColl(myConn As OleDbConnection)
Dim myCommand As OleDbCommand = New OleDbCommand("SELECT * FROM Customers WHERE CustomerID = ?", myConn)
Dim myParamCollection As OleDbParameterCollection = myCommand.Parameters
Dim myParm As Object = New OleDbParameter("CustomerID", OleDbType.VarChar)
Dim pIndex As Integer = myParamCollection.Add(myParm)
Dim myParm As OleDbParameter = myParamCollection.Add(New OleDbParameter("CustomerID", OleDbType.VarChar))
Dim myParm As OleDbParameter = myParamCollection.Add("CustomerID", “CustomerIDValue”);
Dim myParm As OleDbParameter = myParamCollection.Add("CustomerID", OleDbType.VarChar)
Dim myParm As OleDbParameter = myParamCollection.Add("CustomerID", OleDbType.VarChar, 5)
Dim myParm As OleDbParameter = myParamCollection.Add("CustomerID", OleDbType.VarChar, 5, "CustomerID")
End Sub
示例
Public Shared Function CreateCustomerAdapter(conn As OleDbConnection) As OleDbDataAdapter
Dim da As OleDbDataAdapter = New OleDbDataAdapter()
Dim cmd As OleDbCommand
Dim parm As OleDbParameter
' Create the SelectCommand.
cmd = New OleDbCommand("SELECT * FROM Customers WHERE Country = @Country AND City = @City", conn)
cmd.Parameters.Add("@Country", OleDbType.VarChar, 15)
cmd.Parameters.Add("@City", OleDbType.VarChar, 15)
da.SelectCommand = cmd
' Create the InsertCommand.
cmd = New OleDbCommand("INSERT INTO Customers (CustomerID, CompanyName) VALUES (@CustomerID, @CompanyName)", conn)
cmd.Parameters.Add("@CustomerID", OleDbType.Char, 5, "CustomerID")
cmd.Parameters.Add("@CompanyName", OleDbType.VarChar, 40, "CompanyName")
da.InsertCommand = cmd
' Create the DeleteCommand.
cmd = New OleDbCommand("DELETE FROM Customers WHERE CustomerID = @CustomerID", conn)
parm = cmd.Parameters.Add("@CustomerID", OleDbType.Char, 5, "CustomerID")
parm.SourceVersion = DataRowVersion.Original
da.DeleteCommand = cmd
' Create the UpdateCommand.
cmd = New OleDbCommand("UPDATE Customers SET CustomerID = @CustomerID, CompanyName = @CompanyName WHERE CustomerID = @oldCustomerID", conn)
cmd.Parameters.Add("@CustomerID", OleDbType.Char, 5, "CustomerID")
cmd.Parameters.Add("@CompanyName", OleDbType.VarChar, 40, "CompanyName")
parm = cmd.Parameters.Add("@oldCustomerID", OleDbType.Char, 5, "CustomerID")
parm.SourceVersion = DataRowVersion.Original
da.UpdateCommand = cmd
Return da
End Function
以下两行
parm = cmd.Parameters.Add("@CustomerID", OleDbType.Char, 5, "CustomerID")
parm.SourceVersion = DataRowVersion.Original
可以缩写为
cmd.Parameters.Add("@CustomerID", OleDbType.Char, 5, "CustomerID").SourceVersion = DataRowVersion.Original
类似地当添加参数后马上进行设置参数的值时,也可以进行类似以下缩写
myDataAdapter.SelectCommand.Parameters.Add("@CategoryName", OleDbType.VarChar, 80).Value = "toasters"
myDataAdapter.SelectCommand.Parameters.Add("@SerialNum", OleDbType.Integer).Value = 239
(信息整理来自MSDN)