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Вопрос: регистрация и удаление DSN ODBC
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Добавлено: 16.08.06 12:51
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Автор вопроса: Dixon | ICQ: 262-393-953
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Нашел как зарегистрировать DSN: DBEngine.RegisterDatabase
А вот как удалить не знаю.
Ответить
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Номер ответа: 5 Автор ответа: LamerOnLine
ICQ: 334781088
Вопросов: 108 Ответов: 2822
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Профиль | | #5
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Добавлено: 18.08.06 16:14
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Knowledge Base
How To Create and Remove a DSN in Visual BasicPSS ID Number: 171146
Article Last Modified on 6/29/2004
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The information in this article applies to:
Microsoft Visual Basic Professional Edition for Windows 4.0
Microsoft Visual Basic Professional Edition for Windows 5.0
Microsoft Visual Basic Enterprise Edition for Windows 4.0
Microsoft Visual Basic Enterprise Edition for Windows 5.0
Microsoft Visual Basic Standard Edition for Windows 4.0
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This article was previously published under Q171146
SUMMARY
In the 32-bit version of Visual Basic 4.0, it is possible to use DSN-less connections, but because the 16-bit version of ODBC can not handle this syntax, it is not possible to do this in the 16-bit version of Visual Basic 4.0. It is possible to emulate this ability by dynamically creating and removing a Data Source Name (DSN) on the fly using the SQLConfigDataSource ODBC API call.
The following is a 16-and 32-bit example that demonstrates this technique. The 32-bit code was included because this technique has other uses as described below. The 32-bit techniques presented in this article also apply to Visual Basic 5.0.
MORE INFORMATION
The 32-bit ODBC ability to use a DSN-less connection has many uses:
Client Simplicity. The user does not have to worry about setting up a DSN, naming it correctly, setting up options, etc. All this can be done dynamically by the application.
It solves many JET engine connection and connect string caching issues.
Increases the flexibility of the application.
All of these uses can be realized in 16-bit ODBC by creating and deleting a DSN on the fly. This method is also useful for simple DSN management. The code could be used to automatically create, modify, or delete a DSN at any time. Visual Basic does provide the ability to create a DSN using the DBEngine.RegisterDatabase() method, but the API provides greater functionality and the ability to modify and remove a DSN, as well.
Step-by-Step Example
Start a New Project.
In the Advanced tab of the Options dialog box under the Tools menu, set a Conditional Compilation Argument named WIN32 equal to 1 if using Visual Basic 4.0 32-bit, or 0 if using Visual Basic 4.0 16-bit.
Add two CommandButtons to the default form.
Add the following code to the General Declarations:
Option Explicit
'Constant Declaration
Private Const ODBC_ADD_DSN = 1 ' Add data source
Private Const ODBC_CONFIG_DSN = 2 ' Configure (edit) data source
Private Const ODBC_REMOVE_DSN = 3 ' Remove data source
Private Const vbAPINull As Long = 0& ' NULL Pointer
'Function Declare
#If WIN32 Then
Private Declare Function SQLConfigDataSource Lib "ODBCCP32.DLL" _
 ByVal hwndParent As Long, ByVal fRequest As Long, _
ByVal lpszDriver As String, ByVal lpszAttributes As String) _
As Long
#Else
Private Declare Function SQLConfigDataSource Lib "ODBCINST.DLL" _
 ByVal hwndParent As Integer, ByVal fRequest As Integer, ByVal _
lpszDriver As String, ByVal lpszAttributes As String) As Integer
#End If
Add the following code into the Click event of Command1:
#If WIN32 Then
 im intRet As Long
#Else
 im intRet As Integer
#End If
 im strDriver As String
 im strAttributes As String
'Set the driver to SQL Server because it is most common.
strDriver = "SQL Server"
'Set the attributes delimited by null.
'See driver documentation for a complete
'list of supported attributes.
strAttributes = "SERVER=SomeServer" & Chr$(0)
strAttributes = strAttributes & "ESCRIPTION=Temp DSN" & Chr$(0)
strAttributes = strAttributes & "SN=DSN_TEMP" & Chr$(0)
strAttributes = strAttributes & "ATABASE=pubs" & Chr$(0)
'To show dialog, use Form1.Hwnd instead of vbAPINull.
intRet = SQLConfigDataSource(vbAPINull, ODBC_ADD_DSN, _
strDriver, strAttributes)
If intRet Then
MsgBox "SN Created"
Else
MsgBox "Create Failed"
End If
Add the following code into the Click event of Command2:
#If WIN32 Then
 im intRet As Long
#Else
 im intRet As Integer
#End If
 im strDriver As String
 im strAttributes As String
'Set the driver to SQL Server because most common.
strDriver = "SQL Server"
'Set the attributes delimited by null.
'See driver documentation for a complete list of attributes.
strAttributes = "SN=DSN_TEMP" & Chr$(0)
'To show dialog, use Form1.Hwnd instead of vbAPINull.
intRet = SQLConfigDataSource(vbAPINull, ODBC_REMOVE_DSN, _
strDriver, strAttributes)
If intRet Then
MsgBox "SN Deleted"
Else
MsgBox "elete Failed"
End If
Run the project.
Click Command1 to add a DSN named DSN_TEMP.
Click Command2 to remove the DSN named DSN_TEMP.
REFERENCES
ODBC 2.0 Programmer's Reference and SDK Guide
Microsoft Press 1993
ISBN 1-55615-658-8
(c) Microsoft Corporation 1997, All Rights Reserved. Contributions by Troy Cambra, Microsoft Corporation
Keywords: kbhowto KB171146
Technology: kbAudDeveloper kbVB400 kbVB400Search kbVB500 kbVB500Search kbVBSearch kbZNotKeyword2 kbZNotKeyword6
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