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.
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.
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