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DataServer for Microsoft SQL Server
Initial Programming Considerations : Cursors : Forward and backward scrolling
 

Forward and backward scrolling

A query is scrolling if you specify SCROLLING in the DEFINE QUERY statement or if you define a browse for the query. You can use the REPOSITION statement to change your current position with the result set. For a non-scrolling query, the DataServer allows you to only move sequentially forward through the rows by using the FIRST and options of the GET statement. Scrolling basically means that the result set is cached on the client for backward and forward scrolling.
With the DataServer, forward and backward scrolling works with a MS SQL Server just as it does with an OpenEdge database except when the data source fails to find a record. In ABL, the cursor position can change after a failed search; however, with the DataServer, a failed search does not affect the cursor. For example, if a cursor is positioned at custnum 50 and a request for the next customer from an OpenEdge table fails, the cursor moves to the next sequential record beyond custnum 50. The same failed request from a data source leaves the cursor at custnum 50. Your DataServer applications should not assume a certain cursor position after a failed find.
You can, however, still use the AVAILABLE function to determine whether a record is available. The AVAILABLE function behaves consistently whether it accesses an OpenEdge database or a MS SQL Server data source.
* Impact of MAX-ROWS