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

Use external routines - improve performance of application, Use External Ro...

Use External Routines The PL/SQL is particular for the SQL transaction processing. Therefore, several tasks are more quickly completed in a lower-level language like C that is

Using default-declarations in sql, Using DEFAULT You can use the keyword...

Using DEFAULT You can use the keyword DEFAULT rather than that of the assignment operator to initialize the variables. For e.g. the declaration blood_type CHAR := ’O’; it can b

Entering and exiting - autonomous transaction, Entering and Exiting If...

Entering and Exiting If you enter the executable part of an autonomous routine, the major transaction suspends. When you exit the routine, the major transaction resumes. To ex

Best practices/Data Warhousing, What are 3 good practices of modeling and/o...

What are 3 good practices of modeling and/or implementing data warehouses?

Defining autonomous transactions, Defining Autonomous Transactions To ...

Defining Autonomous Transactions To define an autonomous transaction, you use the pragma (compiler directive) AUTONOMOUS_TRANSACTION. The pragma instructs the PL/SQL compiler

I need a ppd-cpa or filesharing site, PPD , CPA, Filesharing Site Projec...

PPD , CPA, Filesharing Site Project Description: This is very easy I need a PPD , CPA, Filesharing Site. [PPD] stands for (pay per download) example hotsharecash [Files

Inner join, Inner Join We have learned how to retrieve data from one t...

Inner Join We have learned how to retrieve data from one table by using SELECT statement. But, as we have learned, normalized relational databases mean the data is spread betw

Why use cursor variables, Why Use Cursor Variables ? Primarily, you use...

Why Use Cursor Variables ? Primarily, you use the cursor variables to pass the query result sets between the PL/SQL stored subprograms and different clients. Neither PL/SQL nor

Boolean values-assignments in pl/sql, Boolean Values Only the values TRU...

Boolean Values Only the values TRUE, FALSE, & NULL can be assigned to a Boolean variable. For illustration, given the declaration DECLARE done BOOLEAN; the following statements

%rowcount - implicit cursor attributes, %ROWCOUNT The %ROWCOUNT yields...

%ROWCOUNT The %ROWCOUNT yields the number of rows affected by the INSERT, UPDATE, or DELETE statement, or returned by a SELECT INTO statement. The %ROWCOUNT yields zero when a

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