MDDatabase

Description

Middleware for producing SQL queries from Markdown

• Quickly create sample schema/data for prototyping or testing
• Investigate how your relational database could be normalized further
• Easily create, update, and manage a static database without having to write any SQL queries

Currently only SQLite is fully supported, with support for MySQL being worked on.

Usage

Headings

For MDDatabase the format of Markdown headings is the following:

[Depth] [Name] ([Type])

Item	Description	Example
Depth	Number of hashes for the depth of this record	##
Name	Name to refer to this unique entity (see "Unique Depth")	Sherlock Holmes
Type	Category of data (singular) that this record represents	occupant

Depth is used when greater than 1 to find and assign a parent (with foreign key references), Name is used to merge duplicate records, and track data-over-time changes, and Type is used to group items, and name the table/table fields (e.g. "occupants", "occupant_uuid").

Properties

For MDDatabase the format of properties is the following, optional under each heading:

-   Property Name: Property Value

"Property Value" by default is considered to be TEXT, but will be tested and converted to INTEGER or REAL if possible.

Unique Depth

Name is used in order to track and refer to data-over-time from other records, however this relies on the name being unique. If the name is not unique this will cause collisions between multiple records, potentially combining their information.

The toSQL() method takes a unique_depth argument (default: 0) in order to instruct MDDatabase to force headings less than or equal to that depth to be unique no matter what (at the moment this has the downside of meaning they cannot be referenced).

Example

With a unique_depth of 1:

# Season 1 (season)

## Episode 1 (episode)

-   Title: Pilot

# Season 2 (season)

## Episode 1 (episode)

-   Title: Seven Thirty-Seven

In this Markdown example, "Season 1" and "Season 2" will always be unique (even if given the same name), however both "Episode 1" records are being interpreted as being the same record (with changes over time), so it would look like the title of episode 1 was changed for some reason in the future.

The ideal solution is to update the headings to be unique ("Pilot" instead of "Episode 1" for example), as this will allow you to refer to these records throughout your data (First Seen In: {Pilot}). Alternatively if this is not possible you can update the unique_depth to 2 when calling toSQL(), but you will not be able to use these unique headings as references.

Code

const { MDDatabase } = require("md-database");

async function main() {
    /**
     * Step 1. Get data
     */
    // from JSON string
    let data = new MDDatabase("[{}, {}, ...]");

    // from array
    let data = new MDDatabase([{}, {}, ...]);

    // from MD string
    let data = MDDatabase.fromMD("# heading ...");

    // from file (.md, .json)
    let data = await MDDatabase.fromFile("./path/to/file.md");

    /**
     * Step 2. Convert data
     */
    // to MD string (duplicates merged, casing cleaned)
    let md = data.toMD();

    // to JSON string
    let json = data.toJSON();

    // to SQL string
    let sql = data.toSQL();

    // to TS string
    let ts = data.toTS();

    // to file (.md, .json, .sql, .ts)
    await data.toFile("./path/to/file.sql");
}

main();

Example

Input: Markdown

# Headquarters (building)

-   House Number: 221b
-   Street: Baker Street
-   City: London
-   Postcode: NW1 6XE

## Sherlock Holmes (occupant)

-   Forename: Sherlock
-   Surname: Holmes

## John Watson (occupant)

-   Forename: John
-   Surname: Watson

Output: Markdown

# Headquarters (building)

-   House Number: 221b
-   Street: Baker Street
-   City: London
-   Postcode: NW1 6XE

## Sherlock Holmes (occupant)

-   Forename: Sherlock
-   Surname: Holmes

## John Watson (occupant)

-   Forename: John
-   Surname: Watson

Output: JSON

[
    {
        "depth": 1,
        "name": "headquarters",
        "type": "building",
        "children": [
            {
                "depth": 2,
                "name": "sherlock holmes",
                "type": "occupant",
                "children": [],
                "properties": {
                    "forename": "Sherlock",
                    "surname": "Holmes"
                }
            },
            {
                "depth": 2,
                "name": "john watson",
                "type": "occupant",
                "children": [],
                "properties": {
                    "forename": "John",
                    "surname": "Watson"
                }
            }
        ],
        "properties": {
            "house number": "221b",
            "street": "Baker Street",
            "city": "London",
            "postcode": "NW1 6XE"
        }
    }
]

Output: SQL

CREATE TABLE IF NOT EXISTS `buildings` (
    `building_uuid` TEXT,
    `building_house_number` TEXT,
    `building_street` TEXT,
    `building_city` TEXT,
    `building_postcode` TEXT,

    PRIMARY KEY (`building_uuid`)
);

CREATE TABLE IF NOT EXISTS `occupants` (
    `occupant_building_uuid` TEXT,
    `occupant_uuid` TEXT,
    `occupant_forename` TEXT,
    `occupant_surname` TEXT,

    PRIMARY KEY (`occupant_building_uuid`, `occupant_uuid`),
    FOREIGN KEY (`occupant_building_uuid`) REFERENCES `buildings` (`building_uuid`)
);

INSERT INTO `buildings`
    (`building_uuid`, `building_house_number`, `building_street`, `building_city`, `building_postcode`) VALUES
    ("87b58a10-f863-404c-aab3-7fa6d55967d0", "221b", "Baker Street", "London", "NW1 6XE");

INSERT INTO `occupants`
    (`occupant_building_uuid`, `occupant_uuid`, `occupant_forename`, `occupant_surname`) VALUES
    ("87b58a10-f863-404c-aab3-7fa6d55967d0", "b064eff0-276c-405b-ae01-48ed60b27f79", "Sherlock", "Holmes"),
    ("87b58a10-f863-404c-aab3-7fa6d55967d0", "2618c3ca-1183-44e8-805e-95e5957be3b7", "John", "Watson");

Output: TS

class MDDatabaseClass<Properties> {
    data: Properties;
    
    constructor(properties: Properties) {
        this.data = properties;
    }
}

export namespace Building {
    export interface Object {
        building_uuid: string;
        building_house_number?: string;
        building_street?: string;
        building_city?: string;
        building_postcode?: string;
    }

    export class Instance extends MDDatabaseClass<Object> {}
}

export namespace Occupant {
    export interface Object {
        occupant_building_uuid: string;
        occupant_uuid: string;
        occupant_forename?: string;
        occupant_surname?: string;
    }

    export class Instance extends MDDatabaseClass<Object> {}
}