Relation Matcher

This is a utility to convert unstructured data from a database into structured relational json data.

Contents

• Installation
• Usage
  • Data
  • Schema
  • Output

Installation

| | Installation Command | | ---- | --------------------------- | | npm | npm i relation-matcher | | yarn | yarn add relation-matcher | | pnpm | pnpm add relation-matcher |

Usage

To use the relation matcher you feed in your data from your database and a schema. For example with drizzle:

import relationMatcher from "relation-matcher";
import db from "~/db/client";

/* Get your data from the database */
const dbData = await db.select().fro...

const data /* Output */ = relationMatcher(
	dbData /* Data */,
	{...} /* Schema */
);

return data;

data

The data's shape should extend:

Array<Record<string, Record<string, unknown> | null>>;

Example

The data could have the following type:

{
	user: {
		id: string;
		email: string;
		password: string;
		...otherColumns
	};

	post: {
		id: string;
		title: string;
		content: string;

		author_id: string; // < Same as user.id
	}
}[]

schema

The schema's shape should be:

{
	base: "name of table",
	id: "distinct column in above table",

	_yourJoinedTableName: {
		base: "name of table to join",
		id: "distinct column of above table",
		joinsFrom: "column of parent table",
		joinsTo: "column of current table",
		joinType: "single" | "array"
	}
}

[!NOTE] Keys for joins start with an underscore; the final property key will have the leading underscore removed.

Example

With the above data, the schema's shape could be:

{
	base: "user",
	id: "id",

	_posts: {
		base: "post",
		id: "id",
		joinsFrom: "id",
		joinsTo: "author_id",
		joinType: "array",
	}
}

output

The outputted data will take the shape of your schema.

Example

For the data and schema provided above, the output will have the following type:

Record<
	string, // The id specified in the root of your schema.
	{
		id: string;
		email: string;
		password: string;
		...otherColumns;

		posts: Array<
			{
				id: string;
				title: string;
				content: string;

				author_id: string;
			}
		>;
	}
>;

Changelog

1.0.13

• Added readme.

1.0.12

• Fixed type issue where return type would be repeated union of expected output.