MiniDB: Mini Database Engine in C++

MiniDB is a simplified database engine implemented in C++, for the purpose of understanding the underlying details of database system. This database engine implements the most basic SQL operations as well as index on B+ tree.

Compile

To compile, you need two open source C++ libraries installed:

cmake
gcc7
readline

run build.bash.

To run it, you need to have global environment variable "HOME" set, the data will be stored at "$HOME/MiniDBData".

Features

Database Management

Create Database

Syntax:  CREATE DATABASE database_name;
Example: CREATE DATABASE abc;

Drop Database

Syntax:  DROP DATABASE database_name;
Example:  DROP DATABASE abc;

Show Databases

Syntax:  SHOW DATABASES;
Example:  SHOW DATABASES;

Syntax:  USE database_name;
Example:  USE abc;

Table Management

Create Table

Syntax:  CREATE TABLE table_name
   (
   column_name1 data_type(size),
   column_name2 data_type(size),
   column_name3 data_type(size),
   ....,
   PRIMARY KEY (column_name)
   );
Example:  CREATE TABLE aaa
   (
   col1 int,
   col2 float,
   col3 char(8),
   PRIMARY KEY (col1)
   );

Note: Available data types include int, float and char(N). Only one primary key could be created.

Drop Table

Syntax:  DROP TABLE table_name;
Example: DROP TABLE aaa;

Show Tables

Syntax:  SHOW TABLES;
Example:  SHOW TABLES;

Index Management

Create Index

Syntax:  CREATE INDEX index_name
   ON table_name (column_name);
Example:  CREATE INDEX aaacol1 
   ON aaa (col1);

Note: Index can only be created on primary key. B+ tree manipulation is implemented in all data manipulation SQLs.

Drop Index

Syntax:  DROP INDEX index_name;
Example: DROP INDEX aaacol1;

Data Manipulation

Insert

Syntax:  INSERT INTO table_name
   VALUES (value1, value2, value3, ...);
Example:  INSERT INTO aaa
   VALUES (111, 222.2, 'xyz');

Select

Syntax:  SELECT * FROM table_name
   WHERE column1 = value1
   and column2 = value2
   and ...;
Example: SELECT * FROM aaa
   WHERE col1 = 111;

Note: Only "and" logic is allowed. Only "*" is allowed.

Delete

Syntax:  DELETE FROM table_name 
   WHERE column1 = value1
   and column2 = value2
   and ...;
Example: DELETE FROM aaa
   WHERE col1 = 111;

Note: Only "and" logic is allowed.

Update

Syntax:  UPDATE table_name
   SET column1 = value1, column2 = value2, ...
   WHERE column1 = value1
   and column2 = value2
   and ...;
Example: UPDATE aaa
   SET col2 = 555.5
   WHERE col1 = 1;

Note: Only "and" logic is allowed.

Other Features Implemented

Help

Syntax:  HELP;
Example:  HELP;

Quit

Syntax:  EXIT
   or
   QUIT
Example: EXIT
   or
   QUIT

Exec

Syntax:  EXEC file_name;
Example:  EXEC input.txt;

Unimplemented Features

Transaction Management
User Management
Authentication
Join
Foreign Keys
Views
Complex Select

Design & Implementation

See wiki.

Test Runs