Fetches the first set of rows from the fileint sm_tm_command ("CONTINUE_TOP [
- The name of a table view in the current transaction. This parameter is case sensitive. If
tableViewNameis specified, the command is applied according to the
tableViewScopeparameter. Since the entire table view tree might not be included, this is known as a partial command, and
tableViewNameis not specified, the command is applied for each table/server view, starting with the root table view. This is known as a full command, and
- One of the following parameters, which must be preceded by a table view name.
TV_AND_BELOWwhich applies the command to the specified table view and all table views below it on the tree. If no parameter is specified, the transaction manager acts as though
CONTINUE_TOP(not available in Web applications or three-tier processing) fetches the first set of rows from the file. The availability of this command is dependent on the setting of the
fetch_directionsproperty for the server view or screen. If the
fetch_directionsproperty is set to
PV_CONT_ALWAYS(Up/Down-all modes), this command is available in update or view mode. If the
fetch_directionsis set to
PV_CONT_VIEW_ONLY(Up/Down-view mode), this command is available only in view mode. Otherwise, an error is generated. For more information on setting the Fetch Directions property, refer to "Scrolling Through the Select Set" in Application Development Guide.
If your screen has multiple table views, the transaction manager issues a
CONTINUE_TOPfor the specified table view and any table views linked to it via server links. This displays the first set of rows for that server view. Then
VIEWprocessing is done for any additional child table views.
The data displayed with this command is from a continuation file: it is not refetched from the database. Therefore, any updates made to the data in this server view either by you, or by another user, are not displayed. In order to display those updates, you must again fetch the data from the database with a
The advantage of using Prolifics's continuation file is that it prevents having shared locks on data. However, if the
fetch_directionsproperty is set to
PV_CONT_ALWAYS(Up/Down-all modes), you are responsible for implementing the necessary locking scheme for concurrent users. For more information on using the Version Column property to implement optimistic locking, refer to "Implementing Optimistic Locking" in Application Development Guide.
If you want to use the database engine's facilities for non-sequential scrolling, you need to add processing for the request events to the engine-specific transaction model.
Push buttons and menu selections for the
CONTINUE_TOPcommand can choose to set the class property to
continue_buttonwhich activates the option only in view and update modes or to
continue_view_buttonwhich activates the option only in view mode.
VIEWwhich generate a database query and display the first set of query results or after any other
Table 8-11 Request event for the CONTINUE_TOP
Request Traversal Typical Processing
The table views in the specified server view
Table 8-12 Request and slice event processing for CONTINUE_TOP
Slices Typical Processing
A select cursor must have been set up for the server view encompassing the current table view or nothing more is done.
sm_tm_continuation_availabilityto check if the command is available. If not, an error is issued.
TM_OCC_COUNTspecifies the maximum number of occurrences to be fetched. If
TM_OCC_COUNTis zero on entry, it means that there is no explicit limit being imposed. The
TM_OCCmember on entry specifies the first occurrence to be fetched into.
TM_OCC_COUNTis then zeroed. (At the end of this re quest,
TM_SEL_CHECKsets it to contain the number of rows fetched.) The data is fetched.
TM_SEL_CHECKis pushed onto the event stack to report the number of rows fetched.
If there was an error in earlier processing, give up the select cursor. Otherwise, report the number of rows fetched to
The following requests can be generated by the
CONTINUE_TOPcommand to ascertain if the changes from the previous command have been saved and, if desired, to discard those changes:
The following requests can also be generated for any child table views:
TM_SELECTfor a parent table view returns no data,
TM_CLEARrequests are generated for all subordinate table views, but not for table views at the same level of the tree.
TM_CLEARrequests are described under