typeorm
diff --git a/.gitignore b/.gitignore
@@ -1 +1,3 @@
-node_modules
+node_modules/
+package-lock.json
+*.db
diff --git a/package.json b/package.json
@@ -22,7 +22,8 @@
     "typeorm-example"
   ],
   "dependencies": {
-    "mysql": "^2.15.0",
-    "typeorm": "^0.2.0"
+    "better-sqlite3": "^8.3.0",
+    "mysql": "^2.18.1",
+    "typeorm": "^0.3.15"
   }
 }
diff --git a/src/app3-es6/entity/CategorySchema.js b/src/app3-es6/entity/CategorySchema.js
diff --git a/src/app3-es6/entity/PostSchema.js b/src/app3-es6/entity/PostSchema.js
diff --git a/src/app3-es6/index.js b/src/app3-es6/index.js
@@ -1,48 +1,33 @@
-const typeorm = require("typeorm"); // import * as typeorm from "typeorm";
-const Post = require("./model/Post").Post; // import {Post} from "./model/Post";
-const Category = require("./model/Category").Category; // import {Category} from "./model/Category";
-
-typeorm.createConnection({
-    type: "mysql",
-    host: "localhost",
-    port: 3306,
-    username: "test",
-    password: "test",
-    database: "test",
-    synchronize: true,
-    logging: false,
-    entities: [
-        require("./entity/PostSchema"),
-        require("./entity/CategorySchema")
-    ]
-}).then(function (connection) {
-
-    const category1 = new Category(0, "TypeScript");
-    const category2 = new Category(0, "Programming");
-
-    return connection
-        .manager
-        .save([category1, category2])
-        .then(() => {
-
-            let post = new Post();
-            post.title = "Control flow based type analysis";
-            post.text = "TypeScript 2.0 implements a control flow-based type analysis for local variables and parameters.";
-            post.categories = [category1, category2];
-
-            let postRepository = connection.getRepository(Post);
-            postRepository.save(post)
-                .then(function(savedPost) {
-                    console.log("Post has been saved: ", savedPost);
-                    console.log("Now lets load all posts: ");
-
-                    return postRepository.find();
-                })
-                .then(function(allPosts) {
-                    console.log("All posts: ", allPosts);
-                });
-        });
-
-}).catch(function(error) {
-    console.log("Error: ", error);
-});
+import { DataSource } from "typeorm";
+
+import Post from "./model/Post.js";
+import Category from "./model/Category.js";
+
+const dataSource = new DataSource({
+  type: "better-sqlite3",
+  database: "app3-es6.db",
+  synchronize: true,
+  logging: false,
+  entities: [Post.schema, Category.schema],
+});
+
+await dataSource.initialize();
+
+const category1 = new Category(1, "TypeScript");
+const category2 = new Category(2, "Programming");
+
+await Category.save([category1, category2]);
+
+const post = new Post();
+post.title = "Control flow based type analysis";
+post.text =
+  "TypeScript 2.0 implements a control flow-based type analysis for local variables and parameters.";
+post.categories = [category1, category2];
+
+const savedPost = await post.save();
+console.log("Post has been saved: ", savedPost);
+console.log("Now lets load all posts: ");
+
+const allPosts = await Post.find({ relations: { categories: true } });
+
+console.log("All posts: ", allPosts);
diff --git a/src/app3-es6/jsconfig.json b/src/app3-es6/jsconfig.json
@@ -0,0 +1,7 @@
+{
+  "compilerOptions": {
+    "checkJs": true,
+    "module": "Node16",
+    "strict": true
+  }
+}
diff --git a/src/app3-es6/model/Category.js b/src/app3-es6/model/Category.js
@@ -1,10 +1,32 @@
-/*export */ class Category {
-    constructor(id, name) {
-        this.id = id;
-        this.name = name;
-    }
+import { BaseEntity, EntitySchema } from "typeorm";
+
+export default class Category extends BaseEntity {
+  /**
+   *
+   * @param {number} [id]
+   * @param {string} [name]
+   */
+  constructor(id, name) {
+    super();
+    this.id = id;
+    this.name = name;
+  }
 }
 
-module.exports = {
-    Category: Category
-};
+/** @satisfies {import('typeorm').EntitySchemaOptions<Record<string, unknown>>} */
+const definition = {
+  name: "Category",
+  columns: {
+    id: {
+      primary: true,
+      type: "int",
+      generated: true,
+    },
+    name: {
+      type: "varchar",
+    },
+  },
+};
+
+Category.definition = definition;
+Category.schema = new EntitySchema({ ...definition, target: Category });
diff --git a/src/app3-es6/model/Post.js b/src/app3-es6/model/Post.js
@@ -1,13 +1,48 @@
-/*export */ class Post {
-    constructor(id, title, text, categories) {
-        this.id = id;
-        this.title = title;
-        this.text = text;
-        this.categories = categories;
-    }
+import { BaseEntity, EntitySchema } from "typeorm";
+
+export default class Post extends BaseEntity {
+  /**
+   *
+   * @param {number} [id]
+   * @param {string} [title]
+   * @param {string} [text]
+   * @param {import('./Category.js').default[]} [categories]
+   */
+  constructor(id, title, text, categories) {
+    super();
+    this.id = id;
+    this.title = title;
+    this.text = text;
+    this.categories = categories;
+  }
 }
 
-module.exports = {
-    Post: Post
+/** @satisfies {import('typeorm').EntitySchemaOptions<Record<string, unknown>>} */
+const definition = {
+  name: "Post",
+  columns: {
+    id: {
+      primary: true,
+      type: "int",
+      generated: true,
+    },
+    title: {
+      type: "varchar",
+    },
+    text: {
+      type: "text",
+    },
+  },
+  relations: {
+    categories: {
+      target: /** @type {const} */ ("Category"),
+      type: "many-to-many",
+      joinTable: true,
+      cascade: true,
+    },
+  },
 };
 
+Post.definition = definition;
+// @ts-expect-error
+Post.schema = new EntitySchema({ ...definition, target: Post });
diff --git a/src/app3-es6/package.json b/src/app3-es6/package.json
@@ -0,0 +1 @@
+{"type": "module"}
diff --git a/src/app3-es6/types/helpers.d.ts b/src/app3-es6/types/helpers.d.ts
@@ -0,0 +1,45 @@
+type Nullables<T> = {
+  [P in keyof T]: T[P] extends { nullable: true } ? P : never;
+}[keyof T];
+
+type Type<T> = T extends "varchar" | "text"
+  ? string
+  : T extends "boolean"
+  ? boolean
+  : T extends "int" | "integer"
+  ? number
+  : T extends "datetime"
+  ? Date
+  : T extends "blob"
+  ? Buffer
+  : unknown;
+
+type ColumnProps<T> = {
+  -readonly [P in keyof T]: Type<T[P]["type"]>;
+};
+
+type Model<T> = import("./models.js").Models[T];
+
+type Relation<T> = T["type"] extends "many-to-many" | "one-to-many"
+  ? Model<T["target"]>[]
+  : T["type"] extends "many-to-one" | "one-to-one"
+  ? Model<T["target"]>
+  : unknown;
+
+type RelationProps<T> = {
+  -readonly [P in keyof T]: Relation<T[P]>;
+};
+
+type Union<A, B> = unknown extends A ? B : unknown extends B ? A : A | B;
+
+type Merge<A, B, N> = {
+  -readonly [P in Exclude<keyof A | keyof B, N>]: Union<A[P], B[P]>;
+} & {
+  -readonly [P in N]?: Union<A[P], B[P]>;
+};
+
+export type EntityProps<T> = Merge<
+  ColumnProps<T["columns"]>,
+  RelationProps<T["relations"]>,
+  Nullables<T["columns"]>
+>;
diff --git a/src/app3-es6/types/models.d.ts b/src/app3-es6/types/models.d.ts
@@ -0,0 +1,21 @@
+import { EntityProps } from "./helpers.js";
+
+/** Add your models here to get automatic types for them */
+
+import Category from "../model/Category.js";
+import Post from "../model/Category.js";
+
+module "../model/Category.js" {
+  export type CategoryProps = EntityProps<typeof Category.definition>;
+  export default interface Category extends CategoryProps {}
+}
+
+module "../model/Post.js" {
+  export type PostProps = EntityProps<typeof Post.definition>;
+  export default interface Post extends PostProps {}
+}
+
+export type Models = {
+  Category: Category;
+  Post: Post;
+};