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

%type attribute - syntax, %TYPE Attribute The %TYPE attribute gives the...

%TYPE Attribute The %TYPE attribute gives the datatype of a record, field, nested table, database column, or the variable. You can use the %TYPE attribute as the datatype speci

Parameter and keyword description - sql cursor, Parameter and Keyword Descr...

Parameter and Keyword Description: SQL: This SQL is the name of the implicit SQL cursor. %FOUND: This attribute results TRUE if an INSERT, DELETE, or UPDATE state

Solve the business problems using sql, Use the MASCOT tables CREDITRS, PORD...

Use the MASCOT tables CREDITRS, PORDS and PAYMENTS to write SQL queries to solve the following business problems. These tables / data are available to you via the USQ Oracle server

Theory of eternity of life - origin of life, THEO R Y OF ETERNITY OF LIFE...

THEO R Y OF ETERNITY OF LIFE (PRAYER - 1880) - The theory of eternity of life, also called the steady-state theory , states that life has ever been in existence as at presen

An active database in pl-sql, Consider the following set of database tables...

Consider the following set of database tables (same tables from Assignment 6-1). Please take note of foreign keys (most of them carry the same names as the corresponding primary ke

Join query, Using a join on 3 tables, select 5 columns and 10 rows from the...

Using a join on 3 tables, select 5 columns and 10 rows from the 3 tables without the use of a Cartesian product Query: SELECT E.LAST_NAME, E.FIRST_NAME, S.BUILDING, S.BRAN

Keyword, what is the use of declare keyword

what is the use of declare keyword

Closing a cursor - explicit cursor, Closing a Cursor The CLOSE stateme...

Closing a Cursor The CLOSE statements disable the cursor, and the result set becomes undefined. An illustration of the CLOSE statement as shown: CLOSE c1;

Parameter and keyword description - records, Parameter and Keyword Descript...

Parameter and Keyword Description: record_type_name: This identifies the user-defined type specifier that is used in the subsequent declarations of the records. NOT N

Join and and in sql, JOIN and AND in SQL In this Section is all about ...

JOIN and AND in SQL In this Section is all about one operator, JOIN. SQL's closest counterpart, NATURAL JOIN, has already been covered. Here we look at several other "join" op

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