heimdall-sequelize-typescript-generator

> Automatically generates typescript models compatible with sequelize-typescript library directly from your source database.

Table of Contents

* Supported databases
* Prerequisites
* Installation
* CLI usage
* Programmatic usage
* Strict mode
* Transform case
* Associations
* One to One
* One to Many
* Many to Many
* Lint

Supported databases

Currently tested databases:

- Postgres (10, 11, 12)
- Mysql (5, 8)
- MariaDB (10)
- SQL Server (2017, 2019)
- SQLite (3)

Prerequisites

See sequelize-typescript installation.

You should also install the specific driver library for your database, see
sequelize documentation:
``shell
npm install -S pg pg-hstore # Postgres
npm install -S mysql2 # MySQL
npm install -S mariadb # MariaDB
npm install -S sqlite3 # SQLite
npm install -S tedious # Microsoft SQL Server
`

Installation


Local install
`shell
npm install -S heimdall-sequelize-typescript-generator
`

Global install (you must install also the peer dependencies globally, see Prerequisites):
`shell
npm install -g heimdall-sequelize-typescript-generator
`

NB - Linting models globally is not supported (eslint library does not support global plugins).
If you plan to use the library globally and you want your models to be automatically linted, you need
to install the following packages locally:

`shell
npm install -S typescript eslint @typescript-eslint/parser
`

CLI usage


To use the library locally, install npx if not already available in the path:
`shell
npm install -g npx
`

Then to get usage information type:
`shell
npx stg --help
`

For a global usage simply type:
`shell
stg --help
`

`shell
Usage: stg -D -d [database] -u [username] -x [password] -h [host] -p
[port] -o [out-dir] -s [schema] -a [associations-file]-t [tables] -T
[skip-tables] -i [indices] -C [case] -S [storage] -L [lint-file] -l [ssl] -r
[protocol] -c [clean]

Options:
--help Show help [boolean]
--version Show version number [boolean]
-h, --host Database IP/hostname [string]
-p, --port Database port. Defaults:
- MySQL/MariaDB: 3306
- Postgres: 5432
- MSSQL: 1433 [number]
-d, --database Database name [string]
-s, --schema Schema name (Postgres only). Default:
- public [string]
-D, --dialect Dialect:
- postgres
- mysql
- mariadb
- sqlite
- mssql [string] [required]
-u, --username Database username [string]
-x, --password Database password [string]
-t, --tables Comma-separated names of tables to process[string]
-T, --skip-tables Comma-separated names of tables to skip [string]
-i, --indices Include index annotations in the generated models
[boolean]
-o, --out-dir Output directory. Default:
- output-models [string]
-c, --clean Clean output directory before running [boolean]
-m, --timestamps Add default timestamps to tables [boolean]
-C, --case Transform tables and fields names
with one of the following cases:
- underscore
- camel
- upper
- lower
- pascal
- const
You can also specify a different
case for model and columns using
the following format:
:
[string]
-S, --storage SQLite storage. Default:
- memory [string]
-L, --lint-file ES Lint file path [string]
-l, --ssl Enable SSL [boolean]
-r, --protocol Protocol used: Default:
- tcp [string]
-a, --associations-file Associations file path [string]
-g, --logs Enable Sequelize logs [boolean]
-n, --dialect-options Dialect native options passed as json string.
[string]
-f, --dialect-options-file Dialect native options passed as json file path.
[string]
-R, --no-strict Disable strict typescript class declaration.
[boolean]
-V, --no-views Disable view generation. Available for: MySQL and MariaDB.
[boolean]
`

Local usage example:
`shell
npx stg -D mysql -h localhost -p 3306 -d myDatabase -u myUsername -x myPassword --indices --dialect-options-file path/to/dialectOptions.json --case camel --out-dir models --clean
`

Global usage example:
`shell
stg -D mysql -h localhost -p 3306 -d myDatabase -u myUsername -x myPassword --indices --dialect-options-file path/to/dialectOptions.json --case camel --out-dir models --clean
`

Programmatic usage

You can use the library programmatically, as shown in the following example:

`ts
import { IConfig, ModelBuilder, DialectMySQL } from 'heimdall-sequelize-typescript-generator';

(async () => {
const config: IConfig = {
connection: {
dialect: 'mysql',
database: 'myDatabase',
username: 'myUsername',
password: 'myPassword'
},
metadata: {
indices: true,
case: 'CAMEL',
},
output: {
clean: true,
outDir: 'models'
},
strict: true,
};

const dialect = new DialectMySQL();

const builder = new ModelBuilder(config, dialect);

try {
await builder.build();
}
catch(err) {
console.error(err);
process.exit(1);
}
})();
`

Strict mode

By default strict mode will be used for models class declaration:

STRICT ENABLED
`ts
import {
Model, Table, Column, DataType, Index, Sequelize, ForeignKey, HasOne
} from "sequelize-typescript";
import { passport } from "./passport";

export interface personAttributes {
person_id: number;
name: string;
passport_id: number;
}

@Table({
tableName: "person",
timestamps: false
})
export class person extends Model implements personAttributes {

@Column({
primaryKey: true,
type: DataType.INTEGER
})
@Index({
name: "PRIMARY",
using: "BTREE",
order: "ASC",
unique: true
})
person_id!: number;

@Column({
type: DataType.STRING(80)
})
name!: string;

@Column({
type: DataType.INTEGER
})
passport_id!: number;

@HasOne(() => passport, {
sourceKey: "person_id"
})
passport?: passport;

}
`

You can disable strict mode from both CLI or programmatically:

`shell
npx stg -D mysql -d myDatabase --no-strict
`

`ts
const config: IConfig = {
connection: {
dialect: 'mysql',
database: 'myDatabase',
username: 'myUsername',
password: 'myPassword'
},
metadata: {
indices: true,
case: 'CAMEL',
},
output: {
clean: true,
outDir: 'models'
},
strict: false,
};
`

STRICT DISABLED
`ts
import {
Model, Table, Column, DataType, Index, Sequelize, ForeignKey, HasOne
} from "sequelize-typescript";
import { passport } from "./passport";

@Table({
tableName: "person",
timestamps: false
})
export class person extends Model {

@Column({
primaryKey: true,
type: DataType.INTEGER
})
@Index({
name: "PRIMARY",
using: "BTREE",
order: "ASC",
unique: true
})
person_id!: number;

@Column({
type: DataType.STRING(80)
})
name!: string;

@Column({
type: DataType.INTEGER
})
passport_id!: number;

@HasOne(() => passport, {
sourceKey: "person_id"
})
passport?: passport;

}
`




Transform case

You can transform table name and fields with one of the following cases:

- underscore
- camel
- upper
- lower
- pascal
- const

You can provide a different case for the model name and columns:

`shell
npx stg -D mysql --case const:camel
`

`ts
const config: IConfig = {
// [...]
metadata: {
case: {
model: 'CONST',
column: 'CAMEL'
},
},
// [...]
};
`

You can also provide your custom transformer function (code only):

`ts
const config: IConfig = {
// [...]
metadata: {
case: (value, target) => {
// Model transformer
if (target === 'model') {
return value.toUpperCase();
}

// Column transformer
return value.toLowerCase();
}
},
// [...]
};
`

NB: please note that currently case transformation is not supported for non ASCII strings.

Associations


Including associations in the generated models requires a bit of manual work unfortunately, but hopefully
it will buy you some time instead of defining them from scratch.

First you have to define a csv-like text file, let's call it associations.csv (but you can call it however you want). In this file you have to put an entry for each association you want to define.
The following associations are supported:

- 1:1
- 1:N
- N:N

Some rules for the association file:

- Names of tables and columns in the associations file must be the native names on the database, not the
transformed names generated when using a custom case transformation with the flag --case.
- Only , separator is supported.
- Do not use enclosing quotes.

Note that fields generated by associations will be pluralized or singularized based on cardinality.

#### One to One
In the associations file include an entry with the following structure:
`
1:1, left_table_key, right_table_key, left_table, right_table
`

where:

- 1:1 is the relation cardinality
- left_table_key is the join column of the left table
- right_table_key is the join column of the right table
- left_table is the name of the left table
- right_table is the name of the right table

For example given the following tables:

`sql
CREATE TABLE person
(
person_id INT PRIMARY KEY,
name VARCHAR(80) NOT NULL,
passport_id INT NOT NULL
);

CREATE TABLE passport
(
passport_id INT PRIMARY KEY,
code VARCHAR(80) NOT NULL
);
`

Define a 1:1 association with the following entry in the associations file:

`
1:1, passport_id, passport_id, person, passport
`

Then pass the associations file path to the cli:
`shell
npx stg -D mysql -h localhost -p 3306 -d myDatabase -u myUsername -x myPassword --indices --associations-file path/to/associations.csv --out-dir models --clean
`

Global:
`shell
stg -D mysql -h localhost -p 3306 -d myDatabase -u myUsername -x myPassword --indices --associations-file path/to/associations.csv --out-dir models --clean
`

Or programmatically:

`ts
import { IConfig, ModelBuilder, DialectMySQL } from 'heimdall-sequelize-typescript-generator';

(async () => {
const config: IConfig = {
connection: {
dialect: 'mysql',
database: 'myDatabase',
username: 'myUsername',
password: 'myPassword'
},
metadata: {
indices: true,
associationsFile: 'path/to/associations.csv',
},
output: {
clean: true,
outDir: 'models'
}
};

const dialect = new DialectMySQL();

const builder = new ModelBuilder(config, dialect);

try {
await builder.build();
}
catch(err) {
console.error(err);
process.exit(1);
}
})();
`

This will generate the following models:

`ts
import {
Model, Table, Column, DataType, Index, ForeignKey, HasOne
} from "sequelize-typescript";
import { passport } from "./passport";

@Table({
tableName: "person",
timestamps: false,
comment: ""
})
export class person extends Model {

@Column({
field: "person_id",
primaryKey: true,
type: DataType.INTEGER
})
@Index({
name: "PRIMARY",
using: "BTREE",
order: "ASC",
unique: true
})
person_id!: number;

@Column({
field: "name",
type: DataType.STRING(80)
})
name!: string;

@Column({
field: "passport_id",
type: DataType.INTEGER
})
@Index({
name: "person_passport_passport_id_fk",
using: "BTREE",
order: "ASC",
unique: false
})
passport_id!: number;

@HasOne(() => passport)
passport?: passport;

}
`

`ts
import {
Model, Table, Column, DataType, Index, ForeignKey, BelongsTo
} from "sequelize-typescript";
import { person } from "./person";

@Table({
tableName: "passport",
timestamps: false,
comment: ""
})
export class passport extends Model {

@ForeignKey(() => person)
@Column({
field: "passport_id",
primaryKey: true,
type: DataType.INTEGER
})
@Index({
name: "PRIMARY",
using: "BTREE",
order: "ASC",
unique: true
})
passport_id!: number;

@Column({
field: "code",
type: DataType.STRING(80)
})
code!: string;

@BelongsTo(() => person)
person?: person;

}
`

#### One to Many

`
1:N, left_table_key, right_table_key, left_table, right_table
`

where:

- 1:N is the relation cardinality
- left_table_key is the join column of the left table
- right_table_key is the join column of the right table
- left_table is the name of the left table
- right_table is the name of the right table

For example given the following tables:

`sql
CREATE TABLE races
(
race_id INT PRIMARY KEY,
race_name VARCHAR(80) NOT NULL
);

CREATE TABLE units
(
unit_id INT PRIMARY KEY,
unit_name VARCHAR(80) NOT NULL,
race_id INT NOT NULL
);
`

Define a 1:N association with the following entry in the associations file:

`
1:N, race_id, race_id, races, units
`

Build models:

`shell
npx stg -D mysql -h localhost -p 3306 -d myDatabase -u myUsername -x myPassword --indices --associations-file path/to/associations.csv --out-dir models --clean
`

This will generate the following models:

`ts
import {
Model, Table, Column, DataType, Index, ForeignKey, HasMany
} from "sequelize-typescript";
import { units } from "./units";

@Table({
tableName: "races",
timestamps: false,
comment: ""
})
export class races extends Model {

@Column({
field: "race_id",
primaryKey: true,
type: DataType.INTEGER
})
@Index({
name: "PRIMARY",
using: "BTREE",
order: "ASC",
unique: true
})
race_id!: number;

@Column({
field: "race_name",
type: DataType.STRING(80)
})
race_name!: string;

@HasMany(() => units)
units?: units[];

}
`

`ts
import {
Model, Table, Column, DataType, Index, ForeignKey, BelongsTo
} from "sequelize-typescript";
import { races } from "./races";

@Table({
tableName: "units",
timestamps: false,
comment: ""
})
export class units extends Model {

@Column({
field: "unit_id",
primaryKey: true,
type: DataType.INTEGER
})
@Index({
name: "PRIMARY",
using: "BTREE",
order: "ASC",
unique: true
})
unit_id!: number;

@Column({
field: "unit_name",
type: DataType.STRING(80)
})
unit_name!: string;

@ForeignKey(() => races)
@Column({
field: "race_id",
type: DataType.INTEGER
})
race_id!: number;

@BelongsTo(() => races)
race?: races;

}
`

#### Many to Many
In the associations file include an entry with the following structure:
`
N:N, left_table_key, right_table_key, left_table, right_table, join_table
`

where:

- N:N is the relation cardinality
- left_table_key is the join column of the left table
- right_table_key is the join column of the right table
- left_table is the name of the left table
- right_table is the name of the right table
- join_table is the name of the join table

For example given the following tables:

`sql
CREATE TABLE authors
(
author_id INT primary key,
full_name VARCHAR(80) not null
);

CREATE TABLE books
(
book_id INT PRIMARY KEY,
title VARCHAR(80) not null
);

CREATE TABLE authors_books
(
author_id INT not null,
book_id INT not null,
PRIMARY KEY (author_id, book_id)
);
`

Define an N:N association with the following entry in the associations file:

`
N:N, author_id, book_id, authors, books, authors_books
`

Build models:

`shell
npx stg -D mysql -h localhost -p 3306 -d myDatabase -u myUsername -x myPassword --indices --associations-file path/to/associations.csv --out-dir models --clean
`

This will generate the following models:

`ts
import {
Model, Table, Column, DataType, Index, ForeignKey, BelongsToMany
} from "sequelize-typescript";
import { books } from "./books";
import { authors_books } from "./authors_books";

@Table({
tableName: "authors",
timestamps: false,
comment: ""
})
export class authors extends Model {

@Column({
field: "author_id",
primaryKey: true,
type: DataType.INTEGER
})
@Index({
name: "PRIMARY",
using: "BTREE",
order: "ASC",
unique: true
})
author_id!: number;

@Column({
field: "full_name",
type: DataType.STRING(80)
})
full_name!: string;

@BelongsToMany(() => books, () => authors_books)
books?: books[];

}
`

`ts
import {
Model, Table, Column, DataType, Index, ForeignKey, BelongsToMany
} from "sequelize-typescript";
import { authors } from "./authors";
import { authors_books } from "./authors_books";

@Table({
tableName: "books",
timestamps: false,
comment: ""
})
export class books extends Model {

@Column({
field: "book_id",
primaryKey: true,
type: DataType.INTEGER
})
@Index({
name: "PRIMARY",
using: "BTREE",
order: "ASC",
unique: true
})
book_id!: number;

@Column({
field: "title",
type: DataType.STRING(80)
})
title!: string;

@BelongsToMany(() => authors, () => authors_books)
authors?: authors[];

}
`

`ts
import {
Model, Table, Column, DataType, Index, ForeignKey
} from "sequelize-typescript";
import { authors } from "./authors";
import { books } from "./books";

@Table({
tableName: "authors_books",
timestamps: false,
comment: ""
})
export class authors_books extends Model {

@ForeignKey(() => authors)
@Column({
field: "author_id",
primaryKey: true,
type: DataType.INTEGER
})
@Index({
name: "PRIMARY",
using: "BTREE",
order: "ASC",
unique: true
})
author_id!: number;

@ForeignKey(() => books)
@Column({
field: "book_id",
primaryKey: true,
type: DataType.INTEGER
})
@Index({
name: "PRIMARY",
using: "BTREE",
order: "ASC",
unique: true
})
book_id!: number;

}
`

Lint

By default each generated model will be linted with a predefined set of rules to improve readability:

`ts
export const eslintDefaultConfig = {
parser: '@typescript-eslint/parser',
parserOptions: {
ecmaVersion: 2018,
sourceType: 'module',
},
plugins: [
'@typescript-eslint',
],
extends: [],
rules: {
'padded-blocks': ['error', { blocks: 'always', classes: 'always', switches: 'always' }],
'lines-between-class-members': ['error', 'always' ],
'object-curly-newline': ['error', {
'ObjectExpression': 'always',
'ObjectPattern': { 'multiline': true },
'ImportDeclaration': { 'multiline': true, 'minProperties': 3 },
'ExportDeclaration': { 'multiline': true, 'minProperties': 3 },
}],
'object-property-newline': ['error'],
'indent': ['error', 'tab'],
},
};
`

You can provide your own set of rules that matches your coding style. Just define a file with the linting rules
(see eslint docs) and pass it to the cli like the following:
`shell
npx stg -D mysql -h localhost -p 3306 -d myDatabase -u myUsername -x myPassword --lint-file path/to/lint-file --out-dir models --clean
`

Globally:
`shell
stg -D mysql -h localhost -p 3306 -d myDatabase -u myUsername -x myPassword --lint-file path/to/lint-file --out-dir models --clean
`

Or you can pass eslint options programmatically:

`ts
import { IConfig, ModelBuilder, DialectMySQL } from 'heimdall-sequelize-typescript-generator';

(async () => {
const config: IConfig = {
connection: {
dialect: 'mysql',
database: 'myDatabase',
username: 'myUsername',
password: 'myPassword'
},
lintOptions: {
configFile: 'path/to/lint-file',
fix: true,
},
output: {
clean: true,
outDir: 'my-models',
},
};

const dialect = new DialectMySQL();

const builder = new ModelBuilder(config, dialect);

await builder.build();
})();
``

License

MIT License