README

--------------------------------------------------------------------------------------

ISHA AGARWAL
Roll No-14075063
B.Tech Part -III
Computer Science and Engineering 

---------------------------------------------------------------------------------------

The file "sql.cpp" contains the code to implement the relational algebra sql operations.
It can implement both nested and simple queries for the following operations :

1)SELECT
2)PROJECT
3)RENAME
4)CARTESIAN PRODUCT
5)UNION
6)SET DIFFERENCE

The user can also 
1)CREATE (tables)
2)INSERT (values into tables)


---------------------------------------------------------------------------------------

How to run?

Open the terminal
cd into the directory where sql.cpp is located.
Run g++ sql.cpp from the terminal
Next run ./a.out

---------------------------------------------------------------------------------------

What does the user see on running the program ?

A mysql> prompt will occur, wherein the user can type the query.
The user will also see the output for some of the queries for the already built-in database.(queries are in the main function)
After the result of those queries user sees a prompt like 
mysql>
The user can exit by typing exit


--------------------------------------------------------------------------------------

What databases will be build ?

The code contains the sql queries to build two tables : student and course automatically.
For this two files of the table name will be generated in the same folder and the code 
the queries to insert data into these tables automatically.

However, the user can also create any new table and insert values also.

--------------------------------------------------------------------------------------

Sample queries and syntax for already built in database :

X : Cartesian Product
U : Union
- : Set Difference
rename : rename

For creation :
create table table_name attr_name1 attr_type1 attr_name2 attr_type2 attr_name3 attr_type3 

For insertion :
insert into table_name attr_name1_val attr_name2_val attr_name3_val 

For select :
( select condition table_name )
In select , condition can have only one condition which can have >, < , = and ! (for not equal to)

For project :
( project attr1 attr2 table_name )

For rename : (rename works with nested query)
( rename new_name table_name )

For cartesian :
table1Xtable2

For unioun :
( query1 U query2 )

For set difference :
( query1 - query2 )

# Nested Queries to be given using ( and )
# There should be space after after ( and )
# The condition of the select statment should not have any space
 
Sample queries given below will reflect the syntax followed : 

1)	create table faculty id int name string address string branch string
2)	insert into student 1 isha bhu cse 101
3)	( select course.credits<d.credits courseX( rename d course ) )
4)	( project name course_id ( select student.course_id=course.course_id ( select branch=cse studentXcourse ) ) )
5)	( project name prof course_id ( select prof=aks ( select * studentXcourse ) ) )"
6)	( ( project course_id prof ( select * course ) ) U ( project course_id prof ( select credits=13 course ) ) )
7)	( project course_id ( select credits=13 course ) )
8)	( project course_id ( select name=arya student ) )
9)	( select credits>12 course )
10)	( project course_id prof ( select * course) ) - ( project course_id prof ( select credits=13 course ) ) )
11)	( project name ( select * student ) )
12)	( select course_id>105 student )
13)	( select * course )
14)	( select * studentXcourse )
15)	( project id name ( select branch=cse student ) )
16)	( project id name student )