This topic summarizes the way that various system processes interact with select-lists.
mvBASIC
Select-lists are available to mvBASIC programs via the READNEXT statement. Such a select-list overrides the first SELECT statement in an mvBASIC program. The select operation may also be initiated by an mvBASIC SELECT statement or an EXECUTE statement in combination with one of the INFO/ACCESS select-list commands.
INFO/ACCESS
An active select-list does not automatically take precedence over parameters specified in the next query. A select-list is ignored, for instance, if the next query includes an explicit item-list. On the other hand, use a selection expression in the subsequent query to access a subset of the items contained in the active select-list.
An explicit item list always takes precedence over an active select-list. For example,
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>SELECT CUSTOMERS WITH LAST-NAME > "NARDONE" 4 ITEMS SELECTED. >LIST-ITEM CUSTOMERS 'TABBO5729' 'GLEBO5687' |
Since neither of the items specified in the LIST-ITEM query were included in the select-list (their last names begin with A and L, respectively), the select-list is ignored and a report is generated for items TABBO5729 and GLEBO5687.
Runoff
The items in a select-list may be inserted into Runoff text via the READNEXT command.
TCL-II Commands
TCL-II commands interact with select-lists just as INFO/ACCESS commands do. The select-list may be overridden by a subsequent command that explicitly references different items in the same file that are not included in the select-list. For more information about TCL-II commands see the mvBase Operation and Administration Guide.
See Also