Biconditional - sql, PL-SQL Programming

Assignment Help:

Biconditional - SQL

The biconditional p ↔ q can be expressed in Tutorial D by p = q and the same is true of SQL. The question then arises as to whether, in SQL, p = q is equivalent to (¬p ∨ q) ∧ (¬q ∨ p). This matter is investigated in the truth table of Figure.

1394_biconditional.png

Figure: SQL p = q ≡ (¬p ∨ q) ∧ (¬q ∨ p)

As you can see, the equivalence does hold in SQL, but only because SQL treats unknown as not equal to-i.e., not the same truth value as-itself ! This treatment of p = q is consistent with the general rule that applies when NULL is an operand of a comparison in SQL.


Related Discussions:- Biconditional - sql

Out mode - parameter modes, OUT Mode An OUT parameter returns values t...

OUT Mode An OUT parameter returns values to the caller of a subprogram. Within the subprogram, an OUT parameter act like a variable. That means that you can use an OUT formal

Example of when or then constraints - sql, Example of WHEN or THEN Constrai...

Example of WHEN or THEN Constraints A concrete example showing how SQL supports WHEN/THEN constraints CREATE TABLE SAL_HISTORY (EmpNo CHAR (6), Salary INTEGER NOT NULL,

Conditionals - sql, Conditionals - SQL At first sight SQL does not app...

Conditionals - SQL At first sight SQL does not appear to have a single operator for expressing logical implication. In this respect it would be in common with most programming

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

Rewrite rules - tautology, Equivalences & Rewrite Rules: If notice tha...

Equivalences & Rewrite Rules: If notice that as well as allowing us to prove trivial theorems, and tautologies enable us to establish that certain sentences are saying the sam

%rowtype - cursors, %ROWTYPE: This attribute gives a record type which ...

%ROWTYPE: This attribute gives a record type which represents a row in the database table or a row fetched from a formerly declared cursor. The Fields in the record and corresp

Package - pl/sql programming, What Is a Package? The package is a sch...

What Is a Package? The package is a schema object that group logically related PL/SQL items, types, and subprograms. The Packages usually have 2 parts, a specification & a bo

Need database development with analysis tools, Need Database Development wi...

Need Database Development with Analysis Tools Project Description: I want a database for large governmental and private data sets on one country that can be simply extended t

Testing triggers, Demonstrate your knowledge of PL/SQL programming by writi...

Demonstrate your knowledge of PL/SQL programming by writing and thoroughly testing triggers and stored procedures associated with an e-commerce application that provides security l

Transactions in sql, Transactions in SQL BEGIN TRANSACTION, COMMIT, an...

Transactions in SQL BEGIN TRANSACTION, COMMIT, and ROLLBACK, SQL has the same syntax except for START in place of BEGIN. However, START TRANSACTION is used only for outermost

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