Micro Focus Visual COBOL 3.0 for Eclipse (Windows) > Programming > Data Access > Database Connectors for Visual COBOL > Database Connectors User's Guide > Database Connectors Overview > Database Concepts

Database Concepts

Restriction: This topic applies only when a Database Connectors license has been installed via the Micro Focus License Management System.

Relational databases differ from indexed file systems in several significant ways. These are the logical associations between database concepts and COBOL indexed file concepts:

Indexed File Concept	Database Concept
Directory	Database
File	Table
Record	Row
Field	Column

Or, put another way:

Database operations are performed on columns. Indexed file operations are performed on records
A COBOL indexed file is logically represented in database table format. Within a table, each column represents one COBOL field; each row represents one COBOL record
Database table columns are strictly associated with a particular data type, such as date, integer, or character. In COBOL, data can have multiple type definitions

For example, for Oracle, a COBOL record that looks like this:

01  terms-record.
    03  terms-code        pic 999.
    03  terms-rate        pic s9v999.
    03  terms-days        pic 9(2).
    03  terms-descript    pic x(15).

would be represented in the database as a table with a format similar to this:

Name	Null	Type
TERMS_CODE	NOT NULL	NUMBER (3)
TERMS_RATE	–	NUMBER (4, 3)
TERMS_DAYS	–	NUMBER (2)
TERMS_DESCRIPT	–	CHAR (15)