title	LocalDBDeleteInstance Function
description	LocalDBDeleteInstance removes the specified SQL Server Express LocalDB instance.
author	markingmyname
ms.author	maghan
ms.reviewer	randolphwest
ms.date	07/14/2025
ms.service	sql
ms.topic	reference
apilocation	sqluserinstance.dll
apiname	LocalDBDeleteInstance
apitype	DLLExport

LocalDBDeleteInstance function

[!INCLUDE SQL Server]

Removes the specified SQL Server Express LocalDB instance.

Header file: msoledbsql.h

Syntax

HRESULT LocalDBDeleteInstance(
           PCWSTR pInstanceName ,
           DWORD dwFlags
);

[Input] The name of the LocalDB instance to remove.

[Input] Reserved for future use. Currently should be set to 0.

S_OK: The function succeeded.

Error	Description
LOCALDB_ERROR_NOT_INSTALLED	SQL Server Express LocalDB isn't installed on the computer.
LOCALDB_ERROR_INVALID_PARAMETER	One or more specified input parameters are invalid.
LOCALDB_ERROR_INVALID_INSTANCE_NAME	The specified instance name is invalid.
LOCALDB_ERROR_UNKNOWN_INSTANCE	The specified instance doesn't exist.
LOCALDB_ERROR_INSTANCE_BUSY	The specified instance is running.
LOCALDB_ERROR_WAIT_TIMEOUT	A timeout occurred while trying to acquire synchronization locks.
LOCALDB_ERROR_INSTANCE_FOLDER_PATH_TOO_LONG	The path where the instance should be stored is longer than MAX_PATH.
LOCALDB_ERROR_CANNOT_GET_USER_PROFILE_FOLDER	A user profile folder can't be retrieved.
LOCALDB_ERROR_CANNOT_ACCESS_INSTANCE_FOLDER	An instance folder can't be accessed.
LOCALDB_ERROR_CANNOT_ACCESS_INSTANCE_REGISTRY	An instance registry can't be accessed.
LOCALDB_ERROR_CANNOT_MODIFY_INSTANCE_REGISTRY	An instance registry can't be modified.
LOCALDB_ERROR_INSTANCE_CONFIGURATION_CORRUPT	An instance configuration is corrupted.
LOCALDB_ERROR_CALLER_IS_NOT_OWNER	API caller isn't Local Database instance owner.
LOCALDB_ERROR_INTERNAL_ERROR	An unexpected error occurred. See the event log for details.

For a code sample that uses LocalDB API, see SQL Server Express LocalDB reference.