pg-typegen

Generate TypeScript type definitions from Postgres database.

Install

$ npm install -D pg-typegen
# or
$ yarn add -D pg-typegen
# or
$ pnpm add -D pg-typegen

Usage

Usage: pg-typegen [options] <connection>
Options:
-V, --version output the version number
-f, --suffix <suffix> suffix to append to generated table type, e.g. item -> ItemEntity (default: "Entity")
-s, --schema <schema> schema (default: "public")
-h, --header <header> header content (default: "")
-o, --output <output> file output path (default: "stdout")
-e, --exclude <exclude> excluded tables and enums as comma separated string e.g. knex_migrations,knex_migrations_lock (default: [])
--type use type definitions instead of interfaces in generated output (default: false)
--semicolons use semicolons in generated types (default: false)
--ssl use ssl (default: false)
--optionals use optionals "?" instead of null (default: false)
--comments generate table and column comments (default: false)
--pascal-enums transform enum keys to pascal case (default: false)
--bigint use bigint for int8 types instead of strings (default: false)
--date-as-string use string for date types instead of javascript Date object (default: false)
--insert-types generate separate insert types with optional fields for columns allowing NULL value or having default values (default: false)
--table-names generate string literal type with all table names (default: false)
--view-names generate string literal types for views and materialized views (default: false)
--help display help for command
Example:
$ pg-typegen -o ./entities.ts postgres://username:password@localhost:5432/database

Given database table

CREATETYPEuser_stateAS ENUM (
'asleep',
'awake'
);
CREATETABLEusers (
id int4 NOT NULL,
name varchar(255),
state user_state,
is_enabled bool NOT NULL DEFAULT FALSE
);

Running pg-typegen -o ./entities.ts postgres://username:password@localhost:5432/database Will generate the following type definitions

enumUserState{asleep='asleep',awake='awake'}interfaceUserEntity{id: number;name: string|null;state: UserState|null;is_enabled: boolean;}

By default, the types will be generated based on how pg returns the values.

Insert types

To simplify database inserts, separate types can be generated with optional values where NULL is allowed or default values for column exist in postgres.

Given database table

CREATETYPEuser_stateAS ENUM (
'asleep',
'awake'
);
CREATETABLEusers (
id serial4 PRIMARY KEY,
name varchar(255) NOT NULL,
state user_state,
is_enabled bool NOT NULL DEFAULT FALSE
);

Running pg-typegen -o ./entities.ts --insert-types postgres://username:password@localhost:5432/database Will generate the following type definitions

enumUserState{asleep='asleep',awake='awake'}interfaceUserEntity{id: number;name: string;state: UserState|null;is_enabled: boolean;}interfaceUserInsertEntity{id?: number;name: string;state?: UserState|null;is_enabled?: boolean;}

Which should allow working with insert objects without having to define all optional and nullable fields.

constuser: UserInsertEntity={name: 'foo'}knex<UserInsertEntity>('users').insert(user)

Running from code

import{join}from'path'importgeneratefrom'pg-typegen';(async()=>{constoutput=join(__dirname,'entities.ts')awaitgenerate({connection: 'postgres://username:password@localhost:5432/database', output })})()

Loading database config

from .env file

export $(grep -v '^#' .env | xargs) && pg-typegen -o ./entities.ts postgres://$DB_USERNAME:$DB_PASSWORD@$DB_HOST:$DB_PORT/$DB_NAME

from json file

pg-typegen -o ./entities.ts postgres://$(jq -r '.DB.USERNAME' config.json):$(jq -r '.DB.PASSWORD' config.json)@$(jq -r '.DB.HOST' config.json):$(jq -r '.DB.PORT' config.json)/$(jq -r '.DB.NAME' config.json)

Run tests

docker-compose up -d
npm test

Use RECREATE_DATABASE=true npm test when running tests for the first time

Contributing

Contributions, issues and feature requests are welcome!

License

Copyright © 2020 Aldis Ameriks.
This project is MIT licensed.