CeMountDBVol (CEDB) (Windows CE 5.0)

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This function issues a mount request for a database volume that contains both data and an integrity log. The function fills a buffer with a CEGUID that is the globally unique identifier (GUID) of a mounted database.

A RAPI version of this function exists called CeMountDBVol (RAPI).

BOOL CeMountDBVol( PCEGUID pceguid,LPWSTR lpszDBVol,DWORD dwFlags);

Parameters

  • pceguid
    [out] Pointer to a buffer that is filled in with the CEGUID of the globally unique identifier of a mounted database.
  • lpszDBVol
    [in] Pointer to the null-terminated string that contains the file name of the database volume to be mounted. The path is limited to MAX_PATH characters and includes the NULL character.
  • dwFlags
    [in] Specification for opening the database volume. The following table shows the possible values for dwFlags.
    Value Description
    CREATE_NEW Creates a new database volume. The function fails if the specified database volume already exists.
    CREATE_ALWAYS Creates a new database volume. The function overwrites the database volume if it exists.
    OPEN_EXISTING Opens the database volume. The function fails if the database volume does not exist.
    OPEN_ALWAYS Opens the database volume if it exists. If the database volume does not exist, the function creates the database volume as if CREATE_NEW was specified.
    TRUNCATE_EXISTING Deletes all data on the volume, including databases and records, and resets the volume locale identifier (LCID). This has the same result as calling DeleteFile on a volume and then calling CeMountDBVol with the CREATE_NEW flag set. The specified volume must not be mounted by an application, or an access denied error will occur.
    EDB_MOUNT_FLAG When set, indicates that an EDB database mount is occurring. When this flag is set, CeMountDbVol has the same effect as CeMountDBVolEx with a NULL pOptions parameter.

Return Values

TRUE indicates success. FALSE indicates failure. To get extended error information, call GetLastError. The following table lists possible values for GetLastError.

Value Description
ERROR_DISK_FULL Returned if the mounted volume does not have space to create the new database.
ERROR_PATH_NOT_FOUND Returned if the specified path was not found.
ERROR_NOT_ENOUGH_MEMORY Returned if there was not enough memory available to create the volume. If the database volume already exists before the function call and dwFlags is CREATE_ALWAYS or OPEN_ALWAYS, GetLastError returns ERROR_ALREADY_EXISTS, even though the function has succeeded.
ERROR_ACCESS_DENIED Returned if dwFlags is set to CREATE_ALWAYS or TRUNCATE_EXISTING, and a database volume with the given name is currently mounted by an application. This error is also returned if the file name refers to a file that is not a valid database volume.
ERROR_ALREADY_EXISTS Returned if dwFlags is set to CREATE_NEW and a database volume with the given name already exists. This error is also returned if a database volume is already mounted with the same CEGUID as the new volume that is being mounted.

**Note   **If the database volume already exists before the function call and dwFlags is CREATE_ALWAYS or OPEN_ALWAYS, CeGetLastError returns ERROR_ALREADY_EXISTS, even though the function has succeeded.

Remarks

The database volume format used in Windows CE 3.0 has changed for Windows CE 4.0 and later. You can use the Database Conversion Wizard, released as part of the Power Toys for Microsoft Pocket PC 2002 to convert CEDB volumes from Windows CE 3.0 to the new format used in Windows CE 4.0 and later. The conversion wizard works with all Windows CE OS designs, not exclusively with Pocket PC. For more information on the Database Conversion Wizard, see this Microsoft Web Site.

The CeMountDBVol function creates a database volume that contains both data and an integrity log. The function can accept any path including Uniform Naming Convention (UNC) names for files on a LAN.

CeMountDBVol is not supported for emulated storage cards created for the Device Emulator through folder sharing.

A single database volume can be mounted more than once by a different application. Each time the volume is mounted, a reference count is incremented. A mounted database volume does not unmount until all applications that mounted the volume call CeUnmountDBVol (CEDB). CeUnmountDBVol must be called to free system resources.

The database volume to be mounted cannot be read-only and the file system that contains the volume must support paging.

It is not necessary to call CeMountDBVol to access the object store. The object store can be regarded as a special database volume that is always mounted.

All data written to a mounted database volume is cached until one of the following occurs:

  • It is explicitly flushed. See CeFlushDBVol (CEDB).
  • It is flushed by the OS because of a low memory condition.
  • It is unmounted.

Requirements

OS Versions: Windows CE 2.10 and later.
Header: Windbase.h.
Link Library: Coredll.lib.

See Also

CeFlushDBVol (CEDB) | CeUnmountDBVol (CEDB) | CHECK_INVALIDGUID

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