Database-with-B-Tree

I implement a simplistic relational database purly in C++ A database application is a computer program whose primary purpose is retrieving information from a computerized database. One of the most popular databases are relational databases. Data items in relational databases has pre-defined relationships between them.

Building a Table:

CREATE TABLE {table name} (column1 type,column2 type,...)

For instance:

CREATE TABLE employee (name string,joinDate timestamp,income int)

Inserting into tables:

INSERT INTO {table name} VALUES (field1,field2,...)

For instance:

INSERT INTO employee VALUES ("Hamid",2022/8/6,45000)

Removing from from table:

DELETE FROM {table name} WHERE {condition}

For instance:

DELETE FROM employee WHERE name=="Hamid"

DELETE FROM employee WHERE income>40000

DELETE FROM employee WHERE joinDate<2022/5/7

Conditions must only consist of == or <>.

Update a record:

UPDATE {table name} SET ("Hamid",2022/8/7,50000) WHERE {condition}

For instance:

UPDATE employee SET ("Hamid",2022/8/7,50000) WHERE name=="Hamid"

Listing records:

SELECT {(column1,column2,...) or *} FROM {table name} WHERE condition

For instance:

SELECT * FROM employee WHERE income>45000
SELECT (name,income) FROM employee WHERE income>45000

Take a look at this example:

CREATE TABLE employee (name string,joinDate timestamp,income int)
INSERT INTO employee VALUES ("Atena",2019/7/6,55000)
INSERT INTO employee VALUES ("Sajede",2020/5/24,20000)
INSERT INTO employee VALUES ("Zahra",2019/4/5,70000)
INSERT INTO employee VALUES ("Narges",2018/4/5,40000)
INSERT INTO employee VALUES ("Mohammad",2020/1/1,67000)