Interesting properties of cross join - sql, PL-SQL Programming

Assignment Help:

Interesting properties of CROSS JOIN - SQL

Compare these with the "interesting properties of JOIN", CROSS JOIN is associative but not commutative. Unlike JOIN and NATURAL JOIN, CROSS JOIN is not idempotent. Let t be any table and let n be its cardinality. Then t CROSS JOIN t has twice as many columns as t and n2 rows. Also unlike JOIN, CROSS JOIN has no identity value. If t is a table, there is no table t0 such that t CROSS JOIN t0 = t. That's because t0 would be required to have no columns and exactly one row, but SQL doesn't recognize the existence of tables with no columns.


Related Discussions:- Interesting properties of cross join - sql

Mixed notation, Mixed Notation The fourth procedure call shows that yo...

Mixed Notation The fourth procedure call shows that you can mix the positional and named notation. In this situation, the first parameter uses the positional notation, & the s

Synonyms- naming conventions, Synonyms You can create the synonyms to pr...

Synonyms You can create the synonyms to provide location transparency for the remote schema objects like tables, views, sequences, stand-alone subprograms, and packages. Though,

Sql is a database language, SQL Is a Database Language: The commands g...

SQL Is a Database Language: The commands given to a DBMS by an application are written in the database language of the DBMS. The term data sublanguage is sometimes used instea

Implicit cursor attributes, Implicit Cursor Attributes The Implicit cur...

Implicit Cursor Attributes The Implicit cursor attributes returns the information about the execution of an INSERT, DELETE, UPDATE, or SELECT INTO statement. The cursor attribu

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

Need azure crm web application with authentication, Need Azure CRM Web Appl...

Need Azure CRM Web Application with two-factor authentication We presently have a CRM-like database stored on MS Azure that we presently access over an MS Access application. It

Row operators - sql operators, Row Operators The Row operators return ...

Row Operators The Row operators return or reference the particular rows. ALL retains the duplicate rows in the result of a query or in an aggregate expression. The DISTINCT el

Change sql file into csv for product registration, Change Sql file into CSV...

Change Sql file into CSV for product registration on Magento Project Description: I have a set of files that are in Sql format and could like for a developer to help me with

Restriction in sql, Restriction in SQL Syntax: SELECT DISTINCT...

Restriction in SQL Syntax: SELECT DISTINCT StudentId FROM IS_CALLED WHERE Name = 'Boris' The WHERE clause operates on the result of the FROM clause in analogo

Cosmozoic theory - origin of life, COSMOZOI C THEORY - Richter (1865...

COSMOZOI C THEORY - Richter (1865) proposed the cosmozoic theory that says that life came by spores (cosmozoa) or other particles from other planets on the earth.

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