NanoDB

SQL database, written as a learning project to better understand the internals of a database.

Features

• A good starting point to dive into database internals
• Modular and extendable architecture
• Implemented widely usable SQL statements (SELECT, INSERT, UPDATE, DELETE, and more)
• Interactive terminal for easy commands execution and experiments

Documentation

• Architecture
• SQL reference
• References

Shell

The NanoDB command line provides an SQL shell that can be used to select, insert, delete, and modify data.

Run locally

git clone https://github.com/i-sevostyanov/NanoDB.git
cd NanoDB
go run ./cmd/repl/main.go
#> \import <path to project>/testdata/demo.sql

Examples:

Imagine that we have a table with the following definition:

CREATE TABLE aircrafts
(
    id    INTEGER PRIMARY KEY,
    code  TEXT    NOT NULL,
    model TEXT    NOT NULL,
    range INTEGER NOT NULL
);

SELECT

Select all columns:

demo #> SELECT * FROM aircrafts
+----+------+---------------------+-------+
| id | code |        model        | range |
+----+------+---------------------+-------+
| 1  | 773  | Boeing 777-300      | 11100 |
| 2  | 763  | Boeing 767-300      | 7900  |
| 3  | SU9  | Sukhoi Superjet-100 | 3000  |
| 4  | 320  | Airbus A320-200     | 5700  |
| 5  | 321  | Airbus A321-200     | 5600  |
| 6  | 319  | Airbus A319-100     | 6700  |
| 7  | 733  | Boeing 737-300      | 4200  |
| 8  | CN1  | Cessna 208 Caravan  | 1200  |
| 9  | CR2  | Bombardier CRJ-200  | 2700  |
+----+------+---------------------+-------+
(9 rows)

Select specified columns with order, limit and offset:

demo #> SELECT id, model, range FROM aircrafts WHERE range < 5000 ORDER BY range ASC LIMIT 5 OFFSET 2
+----+---------------------+-------+
| id |        model        | range |
+----+---------------------+-------+
| 3  | Sukhoi Superjet-100 | 3000  |
| 7  | Boeing 737-300      | 4200  |
+----+---------------------+-------+
(2 rows)

Select expression:

demo #> SELECT 6+(2^3)*5-3+4/(10-2)%3
+----------------------------------------------------+
| (((6 + ((2 ^ 3) * 5)) - 3) + ((4 / (10 - 2)) % 3)) |
+----------------------------------------------------+
| 43                                                 |
+----------------------------------------------------+
(1 rows)

INSERT

demo #> INSERT INTO aircrafts (code, model, range) VALUES ('773', 'Boeing 777-300', 11100);
Query OK, 1 row affected

UPDATE

demo #> UPDATE airports SET code = 'MRN' WHERE id = 2
Query OK, 1 row affected

DELETE

demo #> DELETE FROM airports WHERE id > 5
Query OK, 4 rows affected

Roadmap

• Indices
• Joins
• Subqueries
• Aggregations (count, sum, avg, max, min)
• Explain and query optimization
• Transactions (ACID, MVCC, WAL)
• Constraints (unique key, check, foreign key)
• Built-in functions (sin, cos, abs, floor, etc)

Contributing

Contributions are welcome!

See CONTRIBUTING.md for more details.