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SQLRemoveDriverManager Function

  • Artikel

Conformance
Version Introduced: ODBC 3.0: Deprecated in Windows XP Service Pack 2, Windows Server 2003 Service Pack 1, and later operating systems.

Summary
SQLRemoveDriverManager changes or removes information about the ODBC core components from the Odbcinst.ini entry in the system information.

Syntax

  
BOOL SQLRemoveDriverManager(  
     LPDWORD     pdwUsageCount);

Arguments

pdwUsageCount
[Output] The usage count of the Driver Manager after this function has been called.

Returns

The function returns TRUE if it is successful, FALSE if it fails. If no entry exists in the system information when this function is called, the function returns FALSE.

Diagnostics

When SQLRemoveDriverManager returns FALSE, an associated *pfErrorCode value can be obtained by calling SQLInstallerError. The following table lists the *pfErrorCode values that can be returned by SQLInstallerError and explains each one in the context of this function.

*pfErrorCode Error Description
ODBC_ERROR_GENERAL_ERR General installer error An error occurred for which there was no specific installer error.
ODBC_ERROR_COMPONENT_NOT_FOUND Component not found in registry The installer could not remove the Driver Manager information because it either did not exist in the registry or could not be found in the registry.
ODBC_ERROR_USAGE_UPDATE_FAILED Could not increment or decrement the component usage count The installer failed to decrement the usage count of the Driver Manager.
ODBC_ERROR_OUT_OF_MEM Out of memory The installer could not perform the function because of a lack of memory.

Comments

SQLRemoveDriverManager complements the SQLInstallDriverManager function, and updates the component usage count in the system information. This function should be called only from a setup application.

SQLRemoveDriverManager will decrement the core component usage count by 1. If the component usage count goes to 0, the entry system information will be removed. The core component entry is in the following location in the system information, under the title "ODBC Core":

HKEY_LOCAL_MACHINE

SOFTWARE

ODBC

Odbcinst.ini

Caution

An application should not physically remove Driver Manager files when the component usage count and the file usage count reach zero.

SQLRemoveDriverManager does not actually remove any files. The calling program is responsible for deleting files and maintaining the file usage counts. Driver Manager files should not, however, be removed when both the component usage count and the file usage count have reached zero, because these files may be used by other applications that have not incremented the file usage count.

SQLRemoveDriverManager is called as part of the Uninstall process. ODBC core components (which include the Driver Manager, Cursor Library, Installer, Language Library, Administrator, thunking files, and so on) are uninstalled as a whole. The following files are not removed when SQLRemoveDriverManager is called as part of the Uninstall process:

ODBC32DLL
ODBCCR32.DLL
ODBCCU32.DLL
ODBCINT.DLL
ODBCTRAC.DLL
MSVCRT40.DLL
ODBCCP32.CPL

ODBCCP32.DLL
ODBC16GT.DLL
ODBC32GT.DLL
DS16GT.DLL
DS32GT.DLL
ODBCAD32.EXE

SQLRemoveDriverManager is also called as part of an upgrade process. If an application detects that it has to perform an upgrade and it has previously installed the driver, the driver should be removed and then reinstalled.

SQLRemoveDriverManager should first be called to decrement the component usage count. SQLInstallDriverEx should then be called to increment the component usage count. The application setup program must replace the old core component files with the new files. The file usage counts will remain the same, and other applications that use the older version core component files will now use the newer version files.

For information about See
Installing a Driver Manager SQLInstallDriverManager