Order of evaluation-pl/sql expressions , PL-SQL Programming

Assignment Help:

Order of Evaluation

When you do not use the parentheses to specify the order of evaluation, the operator precedence determine the order. Now compare the expressions below:

NOT (valid AND done)         |       NOT valid AND done


When the Boolean variables valid and complete the value FALSE, the first expression yields TRUE. Though, the second expression yields FALSE as NOT has a higher precedence than AND. So, the second expression is equivalent to:

(NOT valid) AND done
In the example below, notice that if valid has the value FALSE, the entire expression yields FALSE regardless of the value of done:

valid AND done

Similarly, in the next illustration, when valid has the value TRUE, the entire expression yields TRUE regardless of the value of done:

valid OR done


Related Discussions:- Order of evaluation-pl/sql expressions

EXCEPTION handling, set serveroutput on declare a number(5); b numb...

set serveroutput on declare a number(5); b number(5); c number(5); begin a:=&a; b:=&b; c:=a/b; dbms_output.put_line(c); exception when zero_divide then d

I need data entry conversion project, Project Description: This is stage...

Project Description: This is stage 1 of a larger conversion project. We are converting a traditional Server/Client application written in Access 2007 into a web interface with S

Cursor variables, Cursor Variables Similar to a cursor, cursor variable...

Cursor Variables Similar to a cursor, cursor variable points to the current row in the result set of a multi-row query. But, dissimilar a cursor, a cursor variable can be opene

Pragma restrict_references in pl sql, Using Pragma RESTRICT_REFERENCES: ...

Using Pragma RESTRICT_REFERENCES: The function called from the SQL statements should obey certain rules meant to control the side effects. To check for violation of the rules,

%found - explicit cursor attributes, %FOUND Subsequent to a cursor or ...

%FOUND Subsequent to a cursor or cursor variable is opened but before the first fetch, the %FOUND yields NULL. Afterward, it yields TRUE when the last fetch returned a row, or

Enforce security in the database system, Question: (a) In the context o...

Question: (a) In the context of database security explain how the following database features help to enforce security in the database system: (i) Authorisation (ii) Access

Overloading, Overloading The PL/SQL overloads the subprogram names. T...

Overloading The PL/SQL overloads the subprogram names. That is, you can use similar name for few different subprograms as long as their formal parameters differ in the number

Example of group by and collect operator, Example of GROUP BY and COLLECT O...

Example of GROUP BY and COLLECT Operator Example: Using GROUP BY and COLLECT to obtain C_ER2 SELECT CourseId, CAST ( COLLECT (ROW (StudentId, Mark)) AS ROW (Studen

Using raise_application_error - user-defined exceptions, Using raise_applic...

Using raise_application_error The Package DBMS_STANDARD that is supplied with Oracle gives language facilities that help your application to interact with Oracle. For illustra

Closing a cursor variable, Closing a Cursor Variable The CLOSE stateme...

Closing a Cursor Variable The CLOSE statement disables the cursor variable. After that, the related result set is undefined. The syntax for the same is as shown below: CLOS

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd