JetGetDatabaseInfo Function

Artikkel
08/26/2021

Applies to: Windows | Windows Server

JetGetDatabaseInfo Function

The JetGetDatabaseInfo function retrieves various types of information about the database. This API can be called while a database is attached or online (with JetGetDatabaseInfo) or while the database or database engine is offline (with JetGetDatabaseFileInfo).

    JET_ERR JET_API JetGetDatabaseInfo(
      __in          JET_SESID sesid,
      __in          JET_DBID dbid,
      __out         void* pvResult,
      __in          unsigned long cbMax,
      __in          unsigned long InfoLevel
    );

Parameters

sesid

The session to use for this call.

dbid

The JET_DBID for the database to retrieve the information from.

pvResult

Pointer to a buffer which will receive the specified information. The size of the buffer, in bytes, is passed in cbMax.

On failure the contents of pvResult are undefined.

The information stored in pvResult depends on InfoLevel.

cbMax

The size, in bytes, of the buffer that was passed in pvResult.

InfoLevel

InfoLevel specifies which type of information should be retrieved about the specified database. It affects how pvResult is interpreted. Some InfoLevel are available only in the offline (JetGetDatabaseFileInfo) or online (JetGetDatabaseInfo) version of the API.

If the pvResult buffer provided is too small, either JET_errInvalidBufferSize or JET_errBufferTooSmall will be returned depending on the InfoLevel.

Value	Meaning
JET_DbInfoCollate	Not yet supported and return default values. Do not use.
JET_DbInfoConnect	These InfoLevels are deprecated and are not currently supported. Do not use.
JET_DbInfoCountry	Not yet supported and return default values. Do not use.
JET_DbInfoCp	Not yet supported and return default values. Do not use.
JET_DbInfoFilename	pvResult will be interpreted as a string buffer (char *). A MAX_PATH buffer is suggested, however not required. If the buffer is not long enough, JET_errBufferTooSmall will be returned. The string will be populated with the path of the database for this DBID.
JET_DbInfoFilesize	pvResult will be interpreted as a DWORD (4 bytes). Returns the size of the database in pages.
JET_DbInfoIsam	These InfoLevels are deprecated and are not currently supported. Do not use.
JET_DbInfoLCID	(Windows XP and later) This InfoLevel was originally specified as: JET_DbInfoLangid (Windows 2000) pvResult will be interpreted as a long. This returns the Locale identifier (LCID) associate with this database.
JET_DbInfoMisc	pvResult will be interpreted as a JET_DBINFOMISC. The JET_DBINFOMISC structure will be populated with information pertaining to the database specified.
JET_DbInfoOptions	pvResult will be interpreted as a JET_GRBIT (DWORD). This returns whether the database is opened in exclusive mode. If the database is in exclusive mode JET_bitDbExclusive will be set in the JET_GRBIT provided, otherwise zero is set. Note other database grbit options for JetAttachDatabase and JetOpenDatabase are not returned.
JET_DbInfoPageSize	Available only on Windows XP and later. pvResult will be interpreted as an unsigned long. This will return the page size of the database in bytes.
JET_DbInfoSpaceAvailable	pvResult will be interpreted as a DWORD. This returns the available space for the database in pages.
JET_DbInfoSpaceOwned	pvResult will be interpreted as a DWORD. This returns the owned space for the database in pages.
JET_DbInfoTransactions	pvResult will be interpreted as a long. This will return one greater than the maximum level to which transactions can be nested. If JetBeginTransaction is called (in a nesting fashion, that is, on the same session, without a commit or rollback) as many times as this value, on the last call JET_errTransTooDeep will be returned from JetBeginTransaction. Note the value in Windows 2000, Windows XP, and Windows Server 2003 is 7.
JET_DbInfoVersion	pvResult will be interpreted as a long. This returns the database engine's native major version. This value is 0x620 for Windows 2000, Windows XP, and Windows Server 2003.

Return Value

This function returns the JET_ERR datatype with one of the following return codes. For more information about the possible ESE errors, see Extensible Storage Engine Errors and Error Handling Parameters.

Return code	Description
JET_errSuccess	The operation completed successfully.
JET_errBufferTooSmall	The size of the buffer given in cbMax was too small (or not correct) to hold the desired information.
JET_errFeatureNotAvailable	The InfoLevel requested was JET_DbInfoIsam. This is not supported.
JET_errInvalidBufferSize	The size of the buffer given in cbMax was too small (or not correct) to hold the desired information.
JET_errInvalidParameter	One of the parameters provided contained an unexpected value or contained a value that did not make sense when combined with the value of another parameter. This error will be returned by JetGetDatabaseInfo when the JET_DBID provided is not a valid (attached) database. This error will be returned by JetGetDatabaseFileInfo and JetGetDatabaseInfo when an InfoLevel requested is not supported by that version of the function.

On success, the requested data will be returned in the output buffer.

On failure, the output buffer will be in an undefined state.

Requirements

Requirement	Value
Client	Requires Windows Vista, Windows XP, or Windows 2000 Professional.
Server	Requires Windows Server 2008, Windows Server 2003, or Windows 2000 Server.
Header	Declared in Esent.h.
Library	Use ESENT.lib.
DLL	Requires ESENT.dll.
Unicode	Implemented as JetGetDatabaseInfoW (Unicode) and JetGetDatabaseInfoA (ANSI).

Del via

JetGetDatabaseInfo Function