Compiler

Compiler

 

 

A compiler is a specialized computer program that converts source code written in one programming language into another language, usually machine language (also called machine code) so that it can be understood by processors (i.e., logic chips).

Source code is the version of software (usually an application program or an operating system) as it is originally written (i.e., typed into a computer) by a human in plain text (i.e., human readable alphanumeric characters). Source code can be written in any of numerous programming languages, some of the most popular of which are C, C++, Java, Perl, PHP, Python and Tcl/Tk. The output of a compiler is referred to as object code.

Brief History

The first compiler was developed in 1952 by Grace Hopper, a pioneering computer scientist. She said that she invented it because she was lazy and wished that “the programmer may return to being a mathematician.” The first compiler was written using A-0 programming language.

A-0 programming language.

The A-0 system, written by Grace Hopper in 1951 and 1952 for the UNIVAC I, was the first compiler ever developed for an electronic computer.^[1] The A-0 functioned more as a loader or linker than the modern notion of a compiler. A program was specified as a sequence of subroutines and arguments. The subroutines were identified by a numeric code and the arguments to the subroutines were written directly after each subroutine code. The A-0 system converted the specification into machine code that could be fed into the computer a second time to execute the program.

The A-0 system was followed by the A-1, A-2, A-3 (released as ARITH-MATIC), AT-3 (released as MATH-MATIC) and B-0 (released as FLOW-MATIC).

SQL

Running a Query

 

Hello Friends this is as simple as playing a game like ‘Moto GP’. Just read the below given Points and you will be fluent in running queries.

·         Go to http://db.Zoho.com.

·         Now enter your ID and create your database .You can either copy paste the data or yourself create it in the template.

·         Now, in my case I have created 2 data base with names like ‘Employee’ and ‘Department’, you can give any of the random names.

·           Now I want to run a Query to join these 2 databases, in order to do that i have to run a simple query like select name, employee……. from employee database and from department database and put a equal sign in between only if there’s something common in the two databases or one is attribute is a primary key 1 database and foreign key to the another.

·         My second Query was to do the avg. of the salaries of the persons working in a company ’xyz’ , here I selected  Avg. function from the SQL function  given in the insert column and ran the query it gave me the avg. of the salaries of all the 19 persons working in the company.

·         My third Query was to select people who were either have a employee designation as ‘Clerk or were having their age greater then 30, here I selected the attributes required for the final table and gave an or option in the query got the final table.

So, now you can see what a miracle this SQL language is, easy to understand and fast to work with……

Work on it and enjoy……..

ALSO VISIT:

• http://db.zoho.com/ZDBDataSheetView.cc?DBID=19235000000003491&OBJID=19235000000003668

To view my tables

 

 

Library Normalization System

Entities: Book, Subject, Student and Account information

Attributes: Book ISBN No., Book Title, Book Publisher Name, Book Publishing Date and Year, Book Pages, Subject Category ID, Subject Name, Student ID, Student Name, Student Address, Student E-mail ID, Student Telephone No., Account ID, Borrowing, Returning, Fine Collection.

UnNormalized Entity

Book Title

Book Publisher Name

Book Publishing Date and Year

Book Pages

Subject Name

Student Name

Student Address

Student E-mail ID

Student Telephone No.

Borrowing

Returning

Fine Collection

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Normalized Entity

SUBJECT

Subject Category ID PK

BOOK ID FK

Subject Name

STUDENT

Student ID PK

BOOK ID FK

Account ID FK

Student Name

Student Address

Student E-mail ID

Student Telephone No.

Account Information

Account ID PK

Borrowing

Returning

Fine Collection

BOOK

BOOK ISBN No. PK

Book Title

Book Publisher Name

Book Publishing Date and Year

Book Pages