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

Begin parameter description in pl sql, BEGIN Parameter Description in pl sq...

BEGIN Parameter Description in pl sql: BEGIN: This keyword signals the beginning of the executable section of a PL/SQL block, that contains executable statements. The execut

Keys in sql, Keys in SQL SQL support for keys in the following respect...

Keys in SQL SQL support for keys in the following respects: SQL does not require at least one key for every base table. If no key is explicitly declared, then KEY {ALL B

Parameter and keyword description - insert statement, Parameter and Keyword...

Parameter and Keyword Description:   table_reference: This identifies a table or view which should be available when you execute the INSERT statement, and for that you sho

EXCEPTION handling, set serveroutput on declare a number(5); b numb...

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_divide then d

Select into statement - syntax, SELECT INTO Statement   The SELECT INT...

SELECT INTO Statement   The SELECT INTO statement retrieve data from one or more database tables, and then assigns the selected values to the variables or fields. Syntax:

Understanding nested tables, Understanding Nested Tables Within the data...

Understanding Nested Tables Within the database, the nested tables can be considered as one-column database tables. The Oracle stores the rows of a nested table in no specific o

Parameter default values, Parameter Default Values As the illustration ...

Parameter Default Values As the illustration below shows, you can initialize the IN parameters to the default values. In that way, you can pass various numbers of actual par

Merge and truncate in sql, MERGE and TRUNCATE in SQL SQL has two more ...

MERGE and TRUNCATE in SQL SQL has two more table update operators, MERGE and TRUNCATE. MERGE, like INSERT, takes a source table s and uses it to update a target table t. Brief

Mechanistis theory-haeckel - origin of life, MECHANISTI S THEORY-HAECKEL (...

MECHANISTI S THEORY-HAECKEL (1866) - Haeckel stating that after each catalysm, some new organism suddenly forms as a chance event in one stride from inanimate matter and sub

Using raise_application_error - user-defined exceptions, Using raise_applic...

Using raise_application_error The Package DBMS_STANDARD that is supplied with Oracle gives language facilities that help your application to interact with Oracle. For illustra

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