CursorsQL is a primitive but intuitive database in Rust for beginners.

Introduction

CursorsQL is a small database that is easy to learn and use. It is intended for use by people who are newcomers to database technology and SQL.

By design, CursorsQL are minimal and simple, and limited. Even though there are some conveniences CQL offers, CQL is just a stepping stone to true SQL databases like MySQL, SQLite, and PostgresQL,

Unlike the past slow.db and css.db, this project is an actual useable and feasible database that is fast and complete for beginners to database technology.

If something's wrong or doesn't work how you feel, you can open an issue.

Documentation is available here.

Consumption and usage

CursorsDB and CQL are available in one package named @cursorsdottsx/cursorsql, so you can install them with either npm or yarn, or any other package manager.

NPM:

$ npm install @cursorsdottsx/cursorsql

Yarn:

$ yarn add @cursorsdottsx/cursorsql

The package also comes with a CLI you can use by installing the package globally and executing cql or using npx cql.

Types for TypeScript are included as the project frontend is in TypeScript.

There is some configuration and setup required before you use CQL and the database driver, though.

• First you'll need to use cql config to set up CursorsDB.
• Next, use cql to use the CLI.
• Create a new database with the CLI.
• Use the database driver and connect to the database.

Example usage:

import CQLClient from "@cursorsdottsx/cursorsql";

const client = new CQLClient("cql connection string");

await new Promise((resolve, reject) => {
    client.on("ready", () => {
        console.log("Connected to CursorsQL!");

        return resolve();
    });
});

CursorsQL

Introduction

CQL has 6 different kinds of statements and only supports basic CRUD. They are as follows:

• select Reading from the database
• create Creating a new table
• insert Inserting into a table
• upsert Upserting into a table
• update Updating a table
• delete Deleting from a table

Types

CQL supports many primitive types and arrays along with nullables.

• i8 8 bit integer
• i16 16 bit integer
• i32 32 bit integer
• i64 64 bit integer
• u8 unsigned 8 bit integer
• u16 unsigned 16 bit integer
• u32 unsigned 32 bit integer
• u64 unsigned 64 bit integer
• f32 32 bit IEEE-754 floating point
• f64 64 bit IEEE-754 floating point
• bool boolean
• str string
• null null

Suffixing a type with ? will make the type nullable.

Constraints

CQL also has a few column constraints.

The constraints are:

• max can be used to enforce a max value for numbers or max length for strings
• min can be used to enforce a min value for numbers or min length for strings
• unique can be used to enforce a unique column

Modifiers

In addition to constraints, CQL also supports modifiers after a select statement.

Modifiers will modify the output a select statement produces.

Currently, all supported modifiers are:

• order will try to order the results as best as it can (1 for ascending and -1 for descending)
• sort will sort the results by a column (1 for ascending and -1 for descending)
• limit will limit the result count to a maximum value

Syntax

create

create =
'create'
    table
'{'
    ( col type ( ( ( 'max' | 'min' ) number ) | 'unique' )* ',' )*
    ( col type ( ( ( 'max' | 'min' ) number ) | 'unique' )* ( ',' )? )
'}'
';' ;

insert

insert =
'insert'
    table
'{'

    ( '{'
        ( col ( string | number | boolean ) ',' )*
        ( col ( string | number | boolean ) ( ',' )? )
    '}' ',' )*
    ( '{'
        ( col ( string | number | boolean ) ',' )*
        ( col ( string | number | boolean ) ( ',' )? )
    '}' ( ',' )? )
'}'
';' ;

select

select =
'select'
    ( '*' | '{' ( col ',' )* ( col ( ',' )? ) '}' )
'from'
    table
( 'where' '{'
    ( col ( '=' | '!' | '>' | '>=' | '<' | '<=' ) ( string | number | boolean ) ',' )*
    ( col ( '=' | '!' | '>' | '>=' | '<' | '<=' ) ( string | number | boolean ) ( ',' )? )
'}' )?
( ( 'sort' | 'order' | 'limit' ) number )*
';' ;

update

update =
'update'
    table
'{'
    ( col ( string | number | boolean ) ',' )*
    ( col ( string | number | boolean ) ( ',' )? )
'}'
( 'where' '{'
    ( col ( '=' | '!' | '>' | '>=' | '<' | '<=' ) ( string | number | boolean ) ',' )*
    ( col ( '=' | '!' | '>' | '>=' | '<' | '<=' ) ( string | number | boolean ) ( ',' )? )
'}' )?
';' ;

upsert

upsert =
'upsert'
    table
'{'
    ( col ( string | number | boolean ) ',' )*
    ( col ( string | number | boolean ) ( ',' )? )
'}'
'{'
    ( col ( string | number | boolean ) ',' )*
    ( col ( string | number | boolean ) ( ',' )? )
'}'
( 'where' '{'
    ( col ( '=' | '!' | '>' | '>=' | '<' | '<=' ) ( string | number | boolean ) ',' )*
    ( col ( '=' | '!' | '>' | '>=' | '<' | '<=' ) ( string | number | boolean ) ( ',' )? )
'}' )?
';' ;

delete

delete =
'delete'
    table
(
    ( 'where' '{'
        ( col ( '=' | '!' | '>' | '>=' | '<' | '<=' ) ( string | number | boolean ) ',' )*
        ( col ( '=' | '!' | '>' | '>=' | '<' | '<=' ) ( string | number | boolean ) ( ',' )? )
    '}' )?
    ( ( 'sort' | 'order' | 'limit' ) number )*
)?
';' ;

CursorsML

CursorsML is a really simple markup language with little syntax that CursorsDB uses to store metadata.

In the future, more syntax and semantics will be added to provide more efficient methods of storing data.

The documentation has more information on CursorsML.

Contributing

Requirements

• Node.js v16 or newer
• Rust v1.58 or newer

First, install all dependencies with either NPM or Yarn.

NPM:

$ npm install

Yarn:

$ yarn

Next, install dependencies inside the server.

$ cd server/
$ cargo build

Then, create your changes and commit them.

Finally, open a pull request!