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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's 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
);

Arguments

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.

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 instance doesn't 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 can't be accessed.
LOCALDB_ERROR_CANNOT_ACCESS_INSTANCE_REGISTRY An instance registry can't 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.

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