Obtaining a natural join by specifying the common columns, PL-SQL Programming

Assignment Help:

Obtaining a natural join by specifying the common columns

Synatax:

SELECT * FROM IS_CALLED JOIN IS_ENROLLED_ON USING ( StudentId )

However, a named columns join doesn't always have an equivalent formulation using NATURAL JOIN. That's because although each USING column must be a common column, it is not necessary to specify all the common columns.

A common column whose name does not appear in the USING list gives rise to two columns of that name in the result, which therefore does not represent a relation. To cater for cases where the columns used for matching purposes are not common columns, and/or the matching operator is not "=", the required joining condition can be spelled out as shown in Example, in parentheses following the key word ON.


Related Discussions:- Obtaining a natural join by specifying the common columns

Example of coalesce operator - sql, Example of COALESCE operator Examp...

Example of COALESCE operator Example: Give the total of marks for each exam (simplified solution) SELECT CourseId, COALESCE ((SELECT SUM (Mark) FROM EXAM_MARK AS EM

Parameter and keyword description - object types, Parameter and Keyword Des...

Parameter and Keyword Description: type_name: This identifies a user-defined type specifier that is used in the subsequent declarations of the objects. AUTHID Clause:

Using count, Using COUNT The COUNT returns the number of elements that...

Using COUNT The COUNT returns the number of elements that a collection presently contains. For instance, when a varray projects contains 15 elements, then the following IF con

Update command- sql, UPDATE Command- SQL Loosely speaking, UPDATE chan...

UPDATE Command- SQL Loosely speaking, UPDATE changes some of the column values of some existing rows of its target table. Thus, although some rows disappear from the target an

Oracle 10g new features and differences , Oracle 10G new features:- Au...

Oracle 10G new features:- Automatic Database Diagnostic Monitor System Advancements - these methods will provides several methods for extracting reports through the Automatic

Max and min operator in sql, MAX and MIN operator in SQL Example: ...

MAX and MIN operator in SQL Example: (SELECT MAX (Mark) FROM EXAM_MARK WHERE StudentId = 'S1') (SELECT MIN (Mark) FROM EXAM_MARK WHERE StudentId = 'S1') Example

Use serially reusable packages - performance of application, Use Serially R...

Use Serially Reusable Packages To help you to manage the use of memory, the PL/SQL gives the pragma SERIALLY_ REUSABLE that mark some packages as serially reusable . So mark

Package standard, Package STANDARD The package named STANDARD defines t...

Package STANDARD The package named STANDARD defines the PL/SQL atmosphere. The package specification globally declares the exceptions, types, and subprograms that are available

Homework, What are the rates for help in writing PL/SQL procedures and func...

What are the rates for help in writing PL/SQL procedures and functions?

Using extend - collection method, Using EXTEND To enlarge the size of ...

Using EXTEND To enlarge the size of a collection, use EXTEND. This process has 3 forms. The EXTEND appends one null element to a collection. And the EXTEND(n) appends n null e

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