LocalDBGetInstanceInfo Function
Applies to: 
SQL Server
Returns information for the specified SQL Server Express LocalDB instance, such as whether it exists, the LocalDB version it uses, whether it is running, and so on.
The information is returned in a struct named LocalDBInstanceInfo, which has the following definition.
typedef struct _LocalDBInstanceInfo
{
// Contains the size of the LocalDBInstanceInfo struct
DWORD cbLocalDBInstanceInfoSize;
// Holds the instance name
TLocalDBInstanceNamewszInstanceName;
// TRUE if the instance files exist on disk, FALSE otherwise
BOOL bExists;
// TRUE if the instance configuration registry is corrupted, FALSE otherwise
BOOLbConfigurationCorrupted;
// TRUE if the instance is running at the moment, FALSE otherwise
BOOL bIsRunning;
// Holds the LocalDB version for the instance in the format: major.minor.build.revision
DWORD dwMajor;
DWORD dwMinor;
DWORD dwBuild;
DWORD dwRevision;
// Holds the date and time when the instance was started for the last time
FILETIME ftLastStartUTC;
// Holds the name of the TDS named pipe to connect to the instance
WCHARwszConnection;
// TRUE if the instance is shared, FALSE otherwise
BOOLbIsShared;
// Holds the shared name for the instance (if the instance is shared)
TLocalDBInstanceNamewszSharedInstanceName;
// Holds the SID of the instance owner (if the instance is shared)
WCHARwszOwnerSID;
// TRUE if the instance is Automatic, FALSE otherwise
BOOLbIsAutomatic;
} LocalDBInstanceInfo;
Header file: msoledbsql.h
Syntax
HRESULT LocalDBGetInstanceInfo(
PCWSTR wszInstanceName,
PLocalDBInstanceInfo pInstanceInfo,
DWORD dwInstanceInfoSize
);
Parameters
wszInstanceName
[Input] The instance name.
pInstanceInfo
[Output] The buffer to store the information about the LocalDB instance.
dwInstanceInfoSize
[Input] Holds the size of the InstanceInfo buffer.
Returns
S_OK
The function succeeded.
LOCALDB_ERROR_NOT_INSTALLED
SQL Server Express LocalDB is not 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 instance does not exist.
LOCALDB_ERROR_INSTANCE_FOLDER_PATH_TOO_LONG
The path where the instance should be stored is longer than MAX_PATH.
LOCALDB_ERROR_CANNOT_ACCESS_INSTANCE_FOLDER
An instance folder cannot be accessed.
LOCALDB_ERROR_CANNOT_ACCESS_INSTANCE_REGISTRY
An instance registry cannot be accessed.
LOCALDB_ERROR_INSTANCE_CONFIGURATION_CORRUPT
An instance configuration is corrupted.
LOCALDB_ERROR_INTERNAL_ERROR
An unexpected error occurred. See the event log for details.
Details
The rationale behind the introduction of the struct size argument (lpInstanceInfoSize) is to enable the API to return different versions of the LocalDBInstanceInfostruct, effectively enabling forward and backward compatibility.
If the struct size argument (lpInstanceInfoSize) matches the size of a known version of the LocalDBInstanceInfostruct, that version of the struct is returned. Otherwise, LOCALDB_ERROR_INVALID_PARAMETER is returned.
A typical example of LocalDBGetInstanceInfo API usage looks like this:
LocalDBInstanceInfo ii;
LocalDBInstanceInfo(L"Test", &ii, sizeof(LocalDBInstanceInfo));
For a code sample that uses LocalDB API, see SQL Server Express LocalDB Reference.