data.txt

**************************************************************
*                           DB_ENGINE                        *
*                           ---------                        *
*            DATA.TXT: SYNTAX INFORMATION AND EXAMPLES       *
*            -----------------------------------------       *
*                          Shivam Garg                       *
*                           14074017                         *
*	         (shivam.gargcd.cse14@itbhu.ac.in)           *
**************************************************************

                             SYNTAX
                            ========

EXITING THE PROGRAM:
-------------------
EXIT;

SHOWING ALL THE TABLES PRESENT IN THE DATABASE:
SHOW_TABLES;

TABLE CREATION AND DATA INSERTION:
---------------------------------
CREATE table
data_type attribute_name
data_type attribute name
...;

data_type support: INT and CHAR

INSERT table
value11 value12 value13 ...
value21 value22 value23 ...
...;

SYMBOLS FOR RELATIONAL ALGEBRA QUERIES:
--------------------------------------
`  : RENAME
%  : CARTESIAN
@  : SELECT
#  : PROJECT
:  : SET DIFFERENCE
^  : UNION
<  : AGGREGATE

RELATIONAL ALGEBRA QUERIES:
--------------------------
SELECT: @[query](table)
PROJECT: #[list_col](table)
RENAME: `[new_table_name, list_col](table)
UNION: table1 ^ table2
SET-DIFFERENCE: table1 : table2
CARTESIAN PRODUCT: table1 % table2

QUERIES:
-------
query: cond1 op cond2 op cond2 ...
cond: '2'>'4'; Name = 'May'; name = nickname; Age < '53'
op:
*: multiplication
+: addition
-: subtraction
~: not equal to
=: is equal to?
>: greater than
<: less than
!: logical not (unary)
&: logical and (binary)
|: logical or (binary)

Note: column names are written as such, constants (integers and strings)
----  are enclosed within single quotes '<literals>'

AGGREGATE:
---------
{grouping_attributes}?{aggregate_fn}(table)

AGGREGATE FUNCTION:
MAX: max of the values (for integers)
MIN: min of the values (for integers)
AVG: average of the values (for integers)
SUM: sum of the values (for integers)
CNT: count of tuples in each group
CND: count of distinct tuples in each group



                         EXAMPLES
                        ==========

SAMPLE TABLES
-------------
CREATE Student
INT roll
CHAR name
CHAR nick
INT age
INT dept_id;

INSERT Student
1 Ann A 24 1
2 Tom T 23 3
3 Bob B 25 2
4 Liz Liz 6 1
5 Tim T 5 3;

CREATE Dept
INT id
CHAR name ;

INSERT Dept
1 CSE
2 PHY
3 MAT ;

CREATE Student2
INT roll
CHAR name
CHAR nick
INT age
INT dept_id;

INSERT Student2
6 Sia S 27 1
7 Ram R 28 3
3 Bob B 25 2
4 Liz Liz 6 1;

CREATE Student3
INT roll
CHAR name
CHAR nick
INT age
INT dept_id;

INSERT Student3
8 Sam S 23 2
9 Cal C 21 9;


SAMPLE QUERIES
--------------
@[!(roll=age)&!(name=nick)|!('5'>'2.4')|name='Liz'](Student);                            
@[name='Liz'](Student);
@[name='Liz'](@[!(roll=age)&!(name=nick)|!('5'>'2.4')|name='Liz'](Student));
@[name='Liz'](@[(roll=age)&(name>'a' & name<'=a')|('2.40'>'2.4')|name='Liz'](Student));
@['1'~'0'](`[PEOPLE,ID,NAME_ID,ALIAS,AGE_ID,DEPT](Student));
@[Student.dept_id=Dept.id](Student%Dept);
@[name='Liz'](Student)%`[Stud1,ID,NAM,NICK,AGE,DEP](@[name='Liz'](Student));
#[name,roll](@['1'='1'](Student));
#[Student.name, Dept.name](@[Student.dept_id=Dept.id](Student%Dept));
@[Student.dept_id=Dept.id&Student.age>'23'](Student % Dept);

UNION QUERIES
-------------
@['4'~'3'](Student ^ Dept);
@['4'~'3'](Student ^ Student2);
@['4'~'3'](Student2 ^ Student);
@['4'~'3'](Student : Dept);
@['4'~'3'](Student : Student2);
@['4'~'3'](Student2 : Student);
@['4'~'3'](Student2 : Student3);
@['4'~'3'](Student2 % Student3);

AGGREGATE QUERIES
-----------------
CREATE Student
INT roll
CHAR name
CHAR nick
INT age
INT dept_id;

INSERT Student
1 Ann A 24 2
2 Tom T 23 1
3 Bob B 25 2
4 Liz Liz 6 1
5 Tim T 5 3;

#[dept, age, count](
  `[Student, roll, name, nickname, age, dept, sum, oldest, youngest, count](
     {dept_id, age}?{SUM(age), MAX(age), MIN(age), CNT(name)}(Student)
   )
);

DIVISION OPERATOR EXAMPLE
-------------------------

Find those suppliers that supply every product with weight = 13.

CREATE product
INT pno
CHAR pname
INT weight;

INSERT product
1 Nut 13
2 Bold 20
3 Screw 13
4 Cog 5
5 Washer 13;

CREATE supplier
INT sno
INT pno
INT qty;

INSERT supplier
1 1 100
2 4 231
1 5 421
3 4 131
2 1 43
2 3 532
2 5 201;

@['4'~'2'](product);
@['4'~'2'](supplier);
@[supplier.pno = product.pno](supplier % product);
#[sno, pno](supplier);
#[pno](@[weight = '13'](product));
@['1'~'4']( (#[sno](supplier)) % (#[pno](@[weight = '13'](product))) );
@['2'~'4'](
  (`[all, sno, pno]( (#[sno](supplier)) % (#[pno](@[weight = '13'](product)))))
  :
  (#[sno, pno](supplier))
);

{sno}?{}(
  @['1'~'4'](
    (#[sno](supplier))
    :
    (
      #[sno](
        @['2'~'4'](
          (`[all, sno, pno]( (#[sno](supplier)) % (#[pno](@[weight = '13'](product)))))
          :
          (#[sno, pno](supplier))
        )
      )
    )
  )
);

                             ~~ END ~~