Effects of null, PL-SQL Programming

Assignment Help:

Effects of NULL

The numeric variable X, perhaps of type INTEGER, might be assigned NULL. In that case the result of evaluating X + 1 is NULL, and so SET Y = X + 1 assigns NULL to Y. A curious consequence of this is that immediately following this assignment the comparison Y = X + 1 does not evaluate to TRUE. For that matter, neither does the comparison Y = Y. In fact they both evaluate to UNKNOWN.


Related Discussions:- Effects of null

Exit statement - syntax, EXIT Statement   You can use the EXIT stateme...

EXIT Statement   You can use the EXIT statement to exit a loop. The EXIT statement has 2 forms: the conditional EXIT WHEN and the unconditional EXIT. With the either form, you

Semijoin and composition - sql, Semijoin and Composition - SQL For sem...

Semijoin and Composition - SQL For semijoin, the dyadic relational operator MATCHING, defined thus: r1 MATCHING r2, where r1 and r2 are relations such that r1 JOIN r2 is de

Using first and last - collection method, Using FIRST and LAST FIRST a...

Using FIRST and LAST FIRST and LAST return the first and last (minimum and maximum) index numbers in a collection. When the collection is empty, the FIRST and LAST return NULL

Object types - syntax, Object Types An object type is a user-defined co...

Object Types An object type is a user-defined complex datatype which encapsulates the data structure along with the functions and procedures required to manipulate the data. Th

Write sql queries, Write SQL queries to solve the following specifications....

Write SQL queries to solve the following specifications. Include the query AND THE OUTPUT.  A screen dump of the output is acceptable. Show as many rows as you can. A screen dump i

Update stock levels, At times, customers make mistakes in submitting their ...

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

Deleting objects in pl sql, Deleting Objects You can use the DELETE st...

Deleting Objects You can use the DELETE statement to eradicate objects from an object table. To eradicate objects selectively, you use the WHERE clause, as shown below: BEG

Tautologies, Tautologies: Above given table allows us to read the trut...

Tautologies: Above given table allows us to read the truth of the connectives in the next manner. Just expect we are looking at row three. It means this says that, if there P

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

Keyword & parameter description - exceptions, Keyword & Parameter Descripti...

Keyword & Parameter Description: WHEN: This keyword introduces the exception handler. You can have many exceptions execute the similar sequence of the statements by follo

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