Dr. Charles Simonyi is the Father of Modern Microsoft Excel                                           JavaScript was originally developed by Brendan Eich of Netscape under the name Mocha, later LiveScript, and finally renamed to JavaScript.                                           The word "Biology" is firstly used by Lamarck and Treviranus                                           Hippocrates (460-370 bc) is known as father of medicine.                                           Galene, 130-200 is known as father of Experimental Physology                                           Aristotle (384-322 BC) is known as Father of Zoology because he wrote the construction and behavior of different animals in his book "Historia animalium"                                           Theophrastus(370-285 BC) is known as father of Botany because he wrote about 500 different plants in his book "Historia Plantarum".                                           John Resig is known as Father of Jquery -                                          HTML is a markup language which is use to design web pages. It was invented in 1990 by Tim Berners-Lee.                                                                The Google was founded by Larry Page and Sergey Brin.                                                                Rasmus Lerdorf was the original creator of PHP. It was first released in 1995.                                                               Facebook was founded by Mark Zuckerberg                                                               Bjarne Stroustrup, creator of C++.                                                                Dennis Ritchie creator of C                                                                                                                              James Gosling, also known as the "Father of Java"                                          At 11.44%, Bihar is India's fastest growing state                                          Father of HTML -Tim Berners Lee                                          orkut was created by Orkut Büyükkökten, a Turkish software engineer                    Photoshop: It came about after Thomas Knoll, a PhD student at the University of Michigan created a program to display grayscale images on a monochrome monitor which at the time was called 'Display'.


What is a relational database?

A British engineer Ted Codd working for IBM elucidated the theory of relational databases "A Relational Model of Data for Large Shared Data Banks" in the 1970s whilst working for IBM. At the core of this relational model is the concept of normalisation which is the separation of the logical and physical data models. This enables you to "see" the database in a completely different way to its underlying structure.The importance of this separation is that it makes relational databases extremely flexible unlike, for example, hierarchical databases. This flexibility means that either layer can be changed without affecting the other. With  earlier database models, changes in business requirements requiring new data structures necessitated the complete re-design of the database.
A relational database, therefore, can be regarded as containing a set of 2-dimensional tables ("relations") with each table comprising rows ("tuples") and columns ("domains"). Relationships between database tables are created when one table has a column with the same meaning as a column in another table. The actual values of the columns are irrelevant but they must refer to/mean the same thing.
Let's take the example of a very simple database with just 2 tables (tuples):
  • employees
  • departments
the employees table has just three columns :
  • employee_id
  • employee_ name
  • department_id
the department table has just two columns :
  • department_id
  • department_name
There is a relationship between these two tables via the department_id column in each table. The department_id column in the employees table  relates to the department_id column in the departments table. This enables you to assign employees to a department and determine which employees work for which department.

Now that we can say that these two tables are related, the other part of relational database model - relational calculus (which is essentially set theory) enables relations (i.e. database tables) to be combined in various ways:
  • the union of 2 relations results in a set of data containing those elements that exist in one or other relation (or both relations);
  • the result of the join (the intersection) of 2 relations is the set of  elements that exist in both relations;
  • the exclusive "OR" produces the set of items that are in either of the relations but not both
  • an outer-join is the same as the join but also includes elements from one or both relations that are not in the other (depending on whether a full outer-join or a left or right outer join is performed)
  • relations can also be subtracted from each other leaving the set of   elements that were in the first relation but not the 2nd
Let's continue the first of our Oracle tutorials with a few examples, using the following data:
1Mike Jones3
2Phil Rogers6
3Dave Tanner3
4Paul Johnson2
5Raj Patel1
6Qamar Aziz5

Joining employees and departments would produce the following result:
1Marketing5Raj Patel
2Sales4Paul Johnson
3IT3Dave Tanner
The number and data types of the columns must be the same for the union of relations so the departments table requires an extra column. 

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