Retrieval Using the AND Operator

Retrieval Using the `AND` Operator

When AND is used to connect two conditions, each conditional expression must be true for the condition to be true and the row retrieved. If any condition within a compound condition is false, the compound condition is false and the row is not selected.

For example, if you want to retrieve the records of Corporate Division Departments with a budget under $10,000 you can write the following compound condition:

DIV = 'CORP'  AND  BUDGET < 12000

In this example, AND is the logical operator.

Table here illustrates the four possible cases that can occur with the logical operator AND for the compound condition just described.

	Values for	Values for	Condition1	Condition2
	`DIV`	`BUDGET`	`DIV='CORP'`	`BUDGET<12000`	Yields	Row Result
1	`CORP`	`10500`	True	True	True	Retrieved
2	`CORP`	`28000`	True	False	False	Not retrieved
3	`PROD`	`11000`	False	True	False	Not retrieved
4	`PROD`	`27500`	False	False	False	Not retrieved

Table: Logical Operator AND

Example: Based on the above, let's develop a list of departments in the Corporate Division with a budget under $12,000.

If you enter the statement:

SELECT  DNAME, DIV, BUDGET
     FROM    DEPARTMENT
     WHERE   DIV = 'CORP' AND BUDGET < 12000 ;

the result displayed will be:

DNAME                         DIV     BUDGET
  Supplies and Procurement      CORP    10500