BSELECT, BSSELECT
BSELECT retrieves selected items and generates a list comprising the attributes of those items as given by any explicit output-specification or by the default output specification. Each subvalue within these attributes becomes a separate entry within the list. The total number of entries within the list is displayed and the list is made available to the next command or DataBasic program executed as if it had been generated by a list generating command.
BSSELECT is similar, but its output is in item-id order unless sort criteria specify otherwise.
Syntax
BSELECT file-specifier {item-list} {selection-criteria} {USING file-specifier} {sort-criteria} {output-specification} {format-specification} {macro-call} {(options}
BSSELECT file-specifier {item-list} {selection-criteria} {USING file-specifier} {sort-criteria} {output-specification} {format-specification} {macro-call} {(options}
Refer to Sentence Structure for descriptions of these parameters.
Comments
When you press RETURN, the number of elements selected and then the prompt '>' are displayed. Any of the following can then be used to act on the list:
-
Another English sentence. If the list consists of a set of item-ids, another English statement can be entered - for example, LIST or SORT file-specifier {optional clauses}.
-
A Cataloged DataBasic program. The list is then available to the specified program via a READNEXT statement. For more information, refer to the DataBasic Reference.
-
List processing commands - for example, SAVE-LIST.
-
TCL-II commands such as EDIT or COPY.
-
A Proc command. If the BSELECT sentence is processed within a Proc, the list can be accessed via a number of Proc commands. For more information, refer to the Proc Reference.
Note that attributes that are empty are omitted from the list. If required, empty attributes can be included by setting the BSELECT.NULL environment option in your operating environment.
Examples
The following example uses the default output options in the dictionary to determine which attributes are to be captured in the list. There are two default attributes: guest name and leave date:
:BSELECT ROOMS WITH BED-CODE = "Q"
21 ITEMS SELECTED
>SAVE-LIST QBED
[241] 'QBED' CATALOGED
:EDIT-LIST QBED
TOP
.P
001 S
002 Single Occ.
003 Queen
004 68.00
005 Lynch
.
.
.
EOI 021
.EX
'ENGLISH-TUTORIAL*L*QBED' EXITED from file 'POINTER-FILE'.
The following example specifies that the explicit attribute LEAVE-DATE is to be captured in the list:
:BSELECT ROOMS WITH BED-CODE = "Q" LEAVE-DATE 3 ITEMS SELECTED >SAVE-LIST QBED.AVAIL [241] 'QBED.AVAIL' CATALOGED :EDIT-LIST QBED.AVAIL TOP .P 001 09/05/93 002 09/14/93 003 09/11/93 EOF 003 .EX 'ENGLISH-TUTORIAL*L*QBED.AVAIL' EXITED from file 'POINTER-FILE'.