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LOOK.UP; GROUP
Syntax
LOOK.UP; GROUP
The LOOK.UP; GROUP command is used to read Standard, Direct, or Table Component
records into memory. It enables the following details to be specified:
$ The order in which records are retrieved. Use FROM; to read the Component
Ordinates are read in ascending order, or BACK; to read in reverse order.
$ The initial record to be retrieved. This is defined by the start value that follows the
FROM; or BACK; command option.
$ The final record to be retrieved. This is defined by the end value that follows the
UNTIL; command option. If the UNTIL; command option is not included, the loop is
terminated when there are no more records.
Note: The start and end values should not be altered within a LOOK.UP;
GROUP loop.
Caution
The LOOK.UP; GROUP BACK; command will read at least one record (and lock it, if
the SECURE; command option is used) to find out if there are any records in the
specified range. This record will be locked until the end of the transaction. On an
OS 2200 based LINC System, the lock is applied by page and, in the case of a
structure containing 10 records only, for example, they will all be locked until the
end of the transaction.
The record left in memory is not defined when the loop of a LOOK.UP; GROUP command
terminates automatically. The record will differ depending upon the type of host on which
the LINC System is running. The current record will remain in memory following a BREAK;
or JUMP.TO; command.
DD DD DBD DBD DDD
3 3
@D DY
DDDDBDDDDDDDDDDDDDDDDDDDDDDDDDDDDBDDDDBDDDDDDDDDDDDBDDDDDDDDDD
3 3 3 3
@D DD DDY @DD DY
DDDDBDDDDDDDDDDDDDBDDDDBDDDDDDDDDDDDDDDDDDDDDDDDDDBDDDDDDDDDDDD4
3 3 3 3
CDD DD4 @D DD DY
3 3
@DD DY
start value
A data item containing the starting value.
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