COBOL VSAM Files READ with START Logic

Here’s sample COBOL program that shows how to use READ, WRITE and READ NEXT statements. The READ statement is to get record randomly. The READ NEXT to read VSAM file till end of the file.

Establish a Key

START statement positions the cursor. Once position establishes, you can use READ or READ NEXT statements. Below are the examples for that.

MOVE 'xxxxxx' TO key-value
START sample-file 
      KEY IS EQUAL TO key-value
END-START.

READ Statement

The purpose of READ statement is to fetch a record randomly after establishing a key. Here is more on How to Use READ in VSAM Complete Syntax .

READ sample_file RECORD INTO identifier 
KEY IS EQUAL TO key_value 
     INVALID KEY  do_this
     NOT INVALID KEY do_this
END-READ.

READ NEXT Statement

READ Next fetches records sequentially till end of the input VSAM file. Here’s more on VSAM-Basics-Usage.

READ sample_file
    NEXT RECORD INTO identifier KEY IS sample-key
    AT END do_this
    NOT AT END do_this
END-READ.

Note: When you work with VSAM files, the logic READ and READ NEXT helpful to read records.

Write a Record

WRITE record-name FROM identifier
INVALID KEY statement.