UniBasic Commands Reference - Rocket Software

SELECT
Syntax
SELECT file.var [TO {list.num.expr | list.var.expr}] [ON ERROR statements]
SELECT dyn.array [TO {list.num.expr | list.var.expr}] [ON ERROR statements]
Description
The UniBasic SELECT command creates an active select list of all record IDs in a
file. Records appear in the list in the order in which they are stored in the file.
You can access the select list with a READNEXT statement.
The UniBasic SELECT command differs from EXECUTE "SELECT ...", which
executes the UniQuery SELECT command. The UniBasic SELECT command
immediately makes available to READNEXT one group of IDs at a time. The
program does not have to wait for the entire ID list to be constructed.
If changes occur in a group that has not been selected yet, those changes are reflected
in the select list that is being read by the program. If an ID is deleted before the group
is selected by the UniBasic program, that ID does not appear in the list.
Record IDs are truncated at 96 characters when they are copied into the select list.
When using the UniQuery SELECT command, SYSTEM(11) returns the number of
items remaining in the list. With the UniBasic SELECT command, SYSTEM(11)
returns the number of items remaining in the group.
Note: You can specify named or numbered lists (using list.num.expr or list.var.expr)
in BASICTYPEs R and U. Only named lists (list.var.expr) are supported in
BASICTYPEs M and P.
1-702 UniBasic Commands Reference