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Figure 2: Sample Schema

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The following is a Schema for an IMAGE/SQL database called "ORDERS." All the examples in the text are taken from this sample schema.

BEGIN DATA BASE ORDERS;  << CUSTOMER ORDERS >>

PASSWORDS:

4 CLERK;        << SALES CLERK >>
8 SUPER;        << SUPERVISOR OF CUSTOMER ORDERS DEPARTMENT >>
15 DO-ALL;      << PROGRAMMER/ANALYST - CREATOR OF DATA BASE>>

ITEMS:              << (READ / WRITE) >>

ACCOUNT,	    X6   (4,8,15/8,15);	<< CUSTOMER ACCT=AA-NNN	>>
CITY,  	    X14  (4,8,15/8,15);	<< CUSTOMER CITY	>>
DATE,	          X6   (4,8,15/8,15);	<< DATE = DDMMYY	>>
DELIV-DATE,	    X6   (4,8,15/8,15);	<< DEL. DATE = DDMMYY	>>
FIRSTNAME,	    X10  (4,8,15/8,15);	<< CUSTOMER NAME	>>
LASTNAME,	    X16  (4,8,15/8,15);	<< CUSTOMER NAME	>>
PRICE,	          J2   (4,8,15/8,15);	<< PRODUCT UNIT PRICE	>>
QTY,	          J2   (4,8,15/8,15);	<< QUANTITY OF ITEMS	>>
PART-NO,	    X8   (4,8,15/8,15);	<< PRODUCT PART NUMBER	>>
PART-NAME,	    X14  (4,8,15/8,15);	<< PRODUCT DESCRIPTION	>>
STREET,	    X26  (4,8,15/8,15);	<< CUSTOMER STREET ADDR	>>
TOTAL,	          J2   (4,8,15/8,15);	<< TOTAL OF PURCHASES	>>
CREDIT,	    J2   (8,15/8,15); 	<< TOTAL OF PURCHASES	>>
ZIPCODE,	    X6   (4,8,15/8,15);	<< CUSTOMER ZIPCODE	>>

SETS:

NAME:             CUSTOMER,MANUAL(4,8,15/8,15);

ENTRY:            ACCOUNT(1),
                  LASTNAME,
                  FIRSTNAME,
                  STREET,
                  CITY,
                  ZIPCODE;

CAPACITY:         201;

NAME:             DATE-MASTER,AUTOMATIC;

ENTRY:              DATE(1);

CAPACITY:         211;

NAME:             SALES,DETAIL(4,8,15/8,15);

ENTRY:              ACCOUNT(CUSTOMER),
                    DATE(DATE-MASTER),
                    PART-NO,
                    PART-NAME,
                    QTY,
                    PRICE,
                    TOTAL,
                    DELIV-DATE;

CAPACITY:         1231;

END.

The read/write lists associated with each item determine the kind of access users can have. For example, the read/write list associated with the data item CREDIT is

(8,15/8,15);

This means that people who sign on with a password of SUPER or DO-ALL will have read and write access to this item. But people who sign on as CLERK will not be able to access it.

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