In operator-comparison operators, PL-SQL Programming

Assignment Help:

IN Operator

The operator IN tests the set membership. This means "equal to any member of." The set may have nulls, but they are ignored. For illustration, the statement below does not delete the rows in which the ename column is null:

DELETE FROM emp WHERE ename IN (NULL, ’KING’, ’FORD’);

Moreover, the expressions of the form

value NOT IN set

yield FALSE when  the set contains a null. For illustration, instead of deleting the rows in which the ename column is not null and not ’KING’, the statement below deletes no rows:


DELETE FROM emp WHERE ename NOT IN (NULL, ’KING’);


Concatenation Operator

The Double vertical bars (||) serve as the concatenation operator that appends one string to another. For illustration, the expression

’suit’ || ’case’

returns the value as shown below:

’suitcase’

If both the operands have datatype CHAR, the concatenation operator returns a CHAR value. Or else, it returns a VARCHAR2 value.


Related Discussions:- In operator-comparison operators

Projection and existential quantification - sql, Projection and Existential...

Projection and Existential Quantification - SQL Intuitively it might seem that projection in SQL is simply a matter of specifying the required columns in the SELECT clause, a

Declaring records, Declaring Records Whenever you define a RECORD type...

Declaring Records Whenever you define a RECORD type, you may declare records of that type, as the illustration shows: DECLARE TYPE StockItem IS RECORD ( item_no INTEG

Declaring exceptions - user-defined exceptions, Declaring Exceptions T...

Declaring Exceptions The Exceptions can be declared only in the declarative part of the PL/SQL subprogram, block, or package. By introducing its name, you can declare an excep

Multiple assignment - sql, Multiple Assignment- SQL SQL supports mult...

Multiple Assignment- SQL SQL supports multiple assignment to local variables and also applies multiple assignment semantics in SET clauses of UPDATE statements, but does not

Exception handling, set serveroutput on declare a number(5); b n...

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_d

Dynamic ranges- iterative control, Dynamic Ranges The PL/SQL lets you det...

Dynamic Ranges The PL/SQL lets you determine the loop range dynamically at run time, as the example below shows: SELECT COUNT(empno) INTO emp_count FROM emp; FOR i IN 1..emp_cou

Triggers, At times, customers make mistakes in submitting their orders and ...

At times, customers make mistakes in submitting their orders and call to cancel the order. Brewbean’s wants to create a trigger that automatically updates the stock level of all pr

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

Data types and representations, Data Types and Representations This ex...

Data Types and Representations This explains the concept possible representation, abbreviated possrep, and explains how these can be used in conjunction with constraints to de

Use the nocopy compiler hint - performance of application, Use the NOCOPY C...

Use the NOCOPY Compiler Hint By default, the OUT and IN OUT parameters are passed by the value i.e. the value of an IN OUT actual parameter is copied into the corresponding fo

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