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New features are added to PwrDev regurarly.
New is the use of com objects.
The upcomming .NET database 'com wrapper' is a good example to make late bound calls strong typed by using a com object:
Note code like: dr.Connection
Connection is really an object inside dr.
Evt. see also:
New is the use of com objects.
The upcomming .NET database 'com wrapper' is a good example to make late bound calls strong typed by using a com object:
Code:
[b]Local[/b] T [b]As[/b] [b]String[/b]
[b]Local[/b] sSQL [b]As[/b] [b]String[/b]
[b]Local[/b] dr [b]As[/b] VD_CLR_CommonDB_IDataReader
[b]Local[/b] v [b]As[/b] [b]Variant[/b]
[i]' Create a datareader object[/i]
dr = [b]Class[/b] "VD_CLR_CommonDB_DataReader"
[i]' Enable debugging via OutputDebugString() API, for diagnostic purposes only.[/i]
dr.EnableDebug = 1
[i]' Establish a connection.[/i]
[b]If[/b] dr.Connection.Open( _
[b]Empty[/b] _
, "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=BIBLIO.MDB;Persist Security Info=False" ) [b]Then[/b]
[i]' Obtain tablenames[/i]
T = dr.GetTableNames()
[b]If[/b] [b]Len[/b]( T ) = 0 [b]Then[/b] T = dr.LastException.GetLastErrorMessage
[b]VD_Debug_Print[/b] "Tables:" & [b]$CrLf[/b] & T
[i]' Prepare query and parameters, parameters how it should be done(!)[/i]
sSQL = "SELECT TOP 10 * FROM [Authors] WHERE AU_ID < @ID ORDER BY [Author]"
dr.Parameters.Clear()
dr.Parameters.Add("ID", 100, [b]Empty[/b] )
[i]' Use the query to create a reader object, success implies at least one record was found.[/i]
[b]If[/b] dr.Reader.Open( sSQL ) [b]Then[/b]
[i]' Enum fieldnames.[/i]
T = "'" & dr.Reader.Fields.Names() & "'"
[b]VD_Debug_Print[/b] "Fields: " & [b]$CrLf[/b] & T
[i]' Enum records, this is a forward-only recordset.[/i]
[i]' If the read() returns false, the end of the recordset is reached.[/i]
[b]Do[/b]
[i]' Obtain data via a variant and/or wrapper methods to obtain nr's and strings as string.[/i]
dr.Reader.GetFieldData( 0, v )
[b]VD_Debug_Print[/b] [b]Format$[/b]( [b]Variant#[/b]( v ), "0000" ) & ", " & dr.Reader.GetFieldStr( 1 )
[b]Loop[/b] [b]Until[/b] dr.Reader.Read() = 0
[b]VD_Debug_Print[/b] dr.LastException.GetLastErrorMessage
dr.Reader.Close()
[b]End[/b] [b]If[/b]
[b]Else[/b]
T = dr.LastException.GetLastErrorMessage
[b]MsgBox[/b] T
[b]End[/b] [b]If[/b]
[i]' Closing each object in the DataReader class is usually pointless, terminating the DataReader will also close all objects.[/i]
dr.Connection.Close()
dr = [b]Nothing[/b]
Connection is really an object inside dr.
Evt. see also:
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