COBOL Manual for TNS and TNS/R Programs

Procedure Division Verbs

HP COBOL Manual for TNS and TNS/R Programs—522555-006

9-195

READ for Random or Dynamic Access

READ is for random or dynamic access reads a record from a file according to the

value of a key, rather than according to the present value of the file position indicator.

For relative files, READ without NEXT sets the file position indicator to the item

selected by RELATIVE KEY (if KEY is omitted) or to the specified alternate key.

For indexed and queue files, READ without NEXT sets the file position indicator to the

item selected by either the key of reference (if KEY is omitted) or to the specified prime

or alternate key.

When the selected record exists, the process places its contents in the record area. If it

does not exist, an invalid-key condition occurs, and the process executes either the

INVALID KEY statement or, if there is no INVALID KEY phrase, a USE AFTER

EXCEPTION procedure.

When duplicate alternate key values are allowed, the order of records with equal

values depends on the INSERTIONORDER parameter of the alternate key file: records

with duplicate alternate key values are retrieved in either prime key order (the way

NonStop systems software ordinarily works) or in the order in which they were inserted

in the file (as specified in the 1985 ISO/ANSI COBOL standard).