JetGotoPosition Function

Artikkel
08/26/2021

Applies to: Windows | Windows Server

JetGotoPosition Function

The JetGotoPosition function moves a cursor to a new location that is a fraction of the way through the current index. The fraction is approximately equal to the following:

precpos->centriesLT/precpos->centriesTotal

This operation is performed in response to user scroll box input that is received when the user attempts to show data that starts part way through a data set.

    JET_ERR JET_API JetGotoPosition(
      __in          JET_SESID sesid,
      __in          JET_TABLEID tableid,
      __in          JET_RECPOS* precpos
    );

Parameters

sesid

The session to use for this call.

tableid

The cursor to use for this call.

precpos

The description of the fraction to use in positioning the cursor in the current index.

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_errClientRequestToStopJetService	The operation could not complete because all activity on the instance that is associated with the session has ceased as a result of a call to JetStopService.
JET_errInstanceUnavailable	The operation could not complete because the instance that is associated with the session has encountered a fatal error that requires that access to all data be revoked to protect the integrity of that data. Windows XP: This return value is introduced in Windows XP.
JET_errInvalidParameter	The given precpos->cbStruct is not a valid size for the JET_RECPOS structure, or precpos->centriesLT is greater than precpos->centriesTotal.
JET_errNotInitialized	The operation cannot complete because the instance that is associated with the session has not yet been initialized.
JET_errRecordNotFound	This error will be returned if the index is empty.
JET_errRestoreInProgress	The operation cannot complete because a restore operation is in progress on the instance that is associated with the session.
JET_errSessionSharingViolation	The same session cannot be used for more than one thread at the same time. Windows XP: This return value is introduced in Windows XP.
JET_errTermInProgress	The operation cannot complete because the instance that is associated with the session is being shut down.

If this function succeeds, the cursor is moved to a current record that is a fraction of the way through the index where the fraction is precpos->centriesLT divided by precpos->centriesTotal.

If this function fails, the cursor location is left unchanged.

Remarks

This operation moves the cursor through the table to a position at the following approximate point: precpos->centriesLT divided by precpos->centriesTotal.

When updates are occurring continuously on the table, subsequent calls with the same JET_RECPOS can move the cursor to different positions in the index, both before and after the previous position. Transactional isolation does not apply to positioning through JET_RECPOS since it depends on physical properties of the index that are not transaction isolated.

JET_RECPOS should not be used to describe a record within a table or to reposition a record close to an existing record. Instead, bookmarks for an existing record should be retrieved after an initial JetGotoPosition and then used to reposition the same record.

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.

Del via

JetGotoPosition Function