Revamp model system

- Add model relations
- Get rid of SQL_CALC_FOUND_ROWS (deprecated)
- Eager loading

package.json

@@ -1,6 +1,6 @@
 {
   "name": "wms-core",
-  "version": "0.9.3",
+  "version": "0.10.0",
   "description": "Node web framework",
   "repository": "git@gitlab.com:ArisuOngaku/wms-core.git",
   "author": "Alice Gaudon <alice@gaudon.pro>",

src/Utils.ts

@@ -34,6 +34,4 @@ export function cryptoRandomDictionary(size: number, dictionary: string): string
     return output.join('');
 }
 
-export interface Type<T> extends Function {
+export type Type<T> = { new(...args: any[]): T };
-    new(...args: any[]): T
-}

src/auth/AuthGuard.ts

@@ -14,7 +14,7 @@ export default abstract class AuthGuard<P extends AuthProof> {
 
     public async getUserForSession(session: Express.Session): Promise<User | null> {
         if (!await this.isAuthenticated(session)) return null;
-        return await User.getById<User>(`${session.auth_id}`);
+        return await User.getById<User>(session.auth_id);
     }
 
     public async authenticateOrRegister(session: Express.Session, proof: P, registerCallback?: (connection: Connection, userID: number) => Promise<(() => Promise<void>)[]>): Promise<void> {

src/auth/magic_link/MagicLinkAuthController.ts

@@ -59,7 +59,7 @@ export default abstract class MagicLinkAuthController extends Controller {
         const email = req.body.email;
         if (!email) throw new BadRequestError('Email not specified.', 'Please try again.', req.originalUrl);
 
-        let userEmail = await UserEmail.fromEmail(email);
+        let userEmail = await UserEmail.select().where('email', email).first();
         let isRegistration = false;
 
         if (!userEmail) {

src/auth/magic_link/MagicLinkController.ts

@@ -85,7 +85,7 @@ export default abstract class MagicLinkController extends Controller {
 
         let success = true;
         let err;
-        const magicLink = await MagicLink.getById<MagicLink>(`${id}`);
+        const magicLink = await MagicLink.getById<MagicLink>(id);
         if (!magicLink) {
             res.status(404);
             err = `Couldn't find this magic link. Perhaps it has already expired.`;

src/auth/models/MagicLink.ts

@@ -5,7 +5,8 @@ import AuthProof from "../AuthProof";
 import Validator from "../../db/Validator";
 import User from "./User";
 import argon2 from "argon2";
-import {WhereTest} from "../../db/Query";
+import {WhereTest} from "../../db/ModelQuery";
+import UserEmail from "./UserEmail";
 
 export default class MagicLink extends Model implements AuthProof {
     public static async bySessionID(sessionID: string, actionType?: string | string[]): Promise<MagicLink | null> {
@@ -17,8 +18,7 @@ export default class MagicLink extends Model implements AuthProof {
                 query = query.where('action_type', actionType, WhereTest.IN);
             }
         }
-        const links = await this.models<MagicLink>(query.first());
+        return await query.first();
-        return links.length > 0 ? links[0] : null;
     }
 
     public static validityPeriod(): number {
@@ -42,14 +42,14 @@ export default class MagicLink extends Model implements AuthProof {
         }
     }
 
-    protected defineProperties(): void {
+    protected init(): void {
-        this.defineProperty<string>('session_id', new Validator().defined().length(32).unique(this));
+        this.addProperty<string>('session_id', new Validator().defined().length(32).unique(this));
-        this.defineProperty<string>('email', new Validator().defined().regexp(EMAIL_REGEX));
+        this.addProperty<string>('email', new Validator().defined().regexp(EMAIL_REGEX));
-        this.defineProperty<string>('token', new Validator().defined().length(96));
+        this.addProperty<string>('token', new Validator().defined().length(96));
-        this.defineProperty<string>('action_type', new Validator().defined().maxLength(64));
+        this.addProperty<string>('action_type', new Validator().defined().maxLength(64));
-        this.defineProperty<string>('original_url', new Validator().defined().maxLength(1745));
+        this.addProperty<string>('original_url', new Validator().defined().maxLength(1745));
-        this.defineProperty<Date>('generated_at', new Validator());
+        this.addProperty<Date>('generated_at', new Validator());
-        this.defineProperty<boolean>('authorized', new Validator().defined());
+        this.addProperty<boolean>('authorized', new Validator().defined());
     }
 
     public async isOwnedBy(userId: number): Promise<boolean> {
@@ -58,7 +58,10 @@ export default class MagicLink extends Model implements AuthProof {
     }
 
     public async getUser(): Promise<User | null> {
-        return await User.fromEmail(await this.getEmail());
+        const email = await UserEmail.select()
+            .where('email', await this.getEmail())
+            .first();
+        return email ? email.user.get() : null;
     }
 
     public async revoke(): Promise<void> {

src/auth/models/User.ts

@@ -1,54 +1,36 @@
-import UserEmail from "./UserEmail";
 import Model from "../../db/Model";
 import Validator from "../../db/Validator";
 import MysqlConnectionManager from "../../db/MysqlConnectionManager";
 import AddApprovedFieldToUsersTable from "../migrations/AddApprovedFieldToUsersTable";
 import config from "config";
+import {ManyModelRelation} from "../../db/ModelRelation";
+import UserEmail from "./UserEmail";
 
 export default class User extends Model {
-    public static async fromEmail(email: string): Promise<User | null> {
-        const users = await this.models<User>(this.select().where('id', UserEmail.select('user_id').where('email', email).first()).first());
-        return users.length > 0 ? users[0] : null;
-    }
-
-    public static async countAccountsToApprove(): Promise<number> {
-        if (!this.isApprovalMode()) return 0;
-        return (await this.select('COUNT(*) as c').where('approved', false).execute())
-            .results[0]['c'];
-    }
-
-    public static async getUsersToApprove(): Promise<User[]> {
-        if (!this.isApprovalMode()) return [];
-        return await this.models<User>(this.select('users.*', 'ue.email as main_email')
-            .where('approved', false)
-            .leftJoin('user_emails as ue').on('ue.user_id', 'users.id')
-            .where('ue.main', '1'));
-    }
-
     public static isApprovalMode(): boolean {
         return config.get<boolean>('approval_mode') && MysqlConnectionManager.hasMigration(AddApprovedFieldToUsersTable);
     }
 
-    public static async getAdminAccounts(): Promise<User[]> {
-        return await this.models<User>(this.select('users.*', '')
-            .where('is_admin', true)
-            .leftJoin('user_emails as ue').on('ue.user_id', 'users.id')
-            .where('ue.main', true));
-    }
-
     public name?: string;
     public approved: boolean = false;
     public is_admin: boolean = false;
     public created_at?: Date;
     public updated_at?: Date;
 
-    protected defineProperties(): void {
+    public readonly emails = new ManyModelRelation<this, UserEmail>(this, UserEmail, {
-        this.defineProperty<string>('name', new Validator().acceptUndefined().between(3, 64));
+        localKey: 'id',
-        if (User.isApprovalMode()) this.defineProperty<boolean>('approved', new Validator().defined());
+        foreignKey: 'user_id'
-        this.defineProperty<boolean>('is_admin', new Validator().defined());
+    });
 
-        this.defineProperty<Date>('created_at');
+    public readonly mainEmail = this.emails.clone().constraint(q => q.where('main', true));
-        this.defineProperty<Date>('updated_at');
+
+    protected init(): void {
+        this.addProperty<string>('name', new Validator().acceptUndefined().between(3, 64));
+        if (User.isApprovalMode()) this.addProperty<boolean>('approved', new Validator().defined());
+        this.addProperty<boolean>('is_admin', new Validator().defined());
+
+        this.addProperty<Date>('created_at');
+        this.addProperty<Date>('updated_at');
     }
 
     public isApproved(): boolean {

src/auth/models/UserEmail.ts

@@ -1,65 +1,43 @@
 import User from "./User";
 import {Connection} from "mysql";
-import Model, {EMAIL_REGEX, ModelCache} from "../../db/Model";
+import Model, {EMAIL_REGEX} from "../../db/Model";
 import Validator from "../../db/Validator";
 import {query} from "../../db/MysqlConnectionManager";
+import {OneModelRelation} from "../../db/ModelRelation";
 
 export default class UserEmail extends Model {
-    public static async fromEmail(email: any): Promise<UserEmail | null> {
-        const emails = await this.models<UserEmail>(this.select().where('email', email).first());
-        return emails.length > 0 ? emails[0] : null;
-    }
-
-    public static async getMainFromUser(userID: number): Promise<UserEmail | null> {
-        const emails = await this.models<UserEmail>(this.select().where('user_id', userID).where('main', 1).first());
-        return emails.length > 0 ? emails[0] : null;
-    }
-
-    public static async fromUser(userID: number): Promise<UserEmail[] | null> {
-        return await this.models<UserEmail>(this.select().where('user_id', userID));
-    }
-
     public user_id?: number;
     public readonly email!: string;
     private main!: boolean;
     public created_at?: Date;
 
+    public readonly user = new OneModelRelation<this, User>(this, User, {
+        localKey: 'user_id',
+        foreignKey: 'id'
+    });
+
     private wasSetToMain: boolean = false;
 
     constructor(data: any) {
         super(data);
     }
 
-    protected defineProperties(): void {
+    protected init(): void {
-        this.defineProperty<number>('user_id', new Validator().acceptUndefined().exists(User, 'id'));
+        this.addProperty<number>('user_id', new Validator().acceptUndefined().exists(User, 'id'));
-        this.defineProperty<string>('email', new Validator().defined().regexp(EMAIL_REGEX).unique(this));
+        this.addProperty<string>('email', new Validator().defined().regexp(EMAIL_REGEX).unique(this));
-        this.defineProperty<boolean>('main', new Validator().defined());
+        this.addProperty<boolean>('main', new Validator().defined());
-        this.defineProperty<Date>('created_at', new Validator());
+        this.addProperty<Date>('created_at', new Validator());
     }
 
     async beforeSave(exists: boolean, connection: Connection) {
         if (this.wasSetToMain) {
             await query(`UPDATE ${this.table} SET main=false WHERE user_id=${this.user_id}`, null, connection);
-        }
-    }
-
-    protected async afterSave(): Promise<void> {
-        if (this.wasSetToMain) {
             this.wasSetToMain = false;
-            const emails = ModelCache.all(this.table);
-            if (emails) {
-                for (const id in emails) {
-                    const otherEmail = emails[id];
-                    if (otherEmail.id !== this.id && otherEmail.user_id === this.user_id) {
-                        otherEmail.main = false;
-                    }
-                }
-            }
         }
     }
 
     public isMain(): boolean {
-        return !!this.main;
+        return this.main;
     }
 
     public setMain() {

src/db/Model.ts

@@ -1,72 +1,67 @@
 import MysqlConnectionManager, {query} from "./MysqlConnectionManager";
 import Validator from "./Validator";
 import {Connection} from "mysql";
-import Query from "./Query";
+import ModelQuery, {ModelQueryResult} from "./ModelQuery";
 import {Request} from "express";
-import Pagination from "../Pagination";
+import {Type} from "../Utils";
+
+export interface ModelClass<M extends Model> extends Type<M> {
+    getFactory<M extends Model>(factory?: ModelFactory<M>): ModelFactory<M>;
+
+    table: string;
+
+    getPrimaryKey(modelData: any): string;
+
+    getPrimaryKeyFields(): string[];
+
+    select<M extends Model>(...fields: string[]): ModelQuery<M>;
+
+    update<M extends Model>(data: { [key: string]: any }): ModelQuery<M>;
+
+    delete<M extends Model>(): ModelQuery<M>;
+}
 
 export default abstract class Model {
-    public static async getById<T extends Model>(id: string): Promise<T | null> {
+    public static get table(): string {
-        const cachedModel = ModelCache.get(this.table, id);
+        return this.name
-        if (cachedModel?.constructor === this) {
+                .replace(/(?:^|\.?)([A-Z])/g, (x, y) => '_' + y.toLowerCase())
-            return <T>cachedModel;
+                .replace(/^_/, '')
-        }
+            + 's';
-
-        const models = await this.models<T>(this.select().where('id', id).first());
-        return models.length > 0 ? models[0] : null;
     }
 
-    public static async paginate<T extends Model>(request: Request, perPage: number = 20, query?: Query): Promise<T[]> {
+    public static async getById<T extends Model>(this: ModelClass<T>, id: number): Promise<T | null> {
+        return this.select<T>().where('id', id).first();
+    }
+
+    public static async paginate<T extends Model>(this: ModelClass<T>, request: Request, perPage: number = 20, query?: ModelQuery<T>): Promise<ModelQueryResult<T>> {
         let page = request.params.page ? parseInt(request.params.page) : 1;
         if (!query) query = this.select();
-        query = query.limit(perPage, (page - 1) * perPage).withTotalRowCount();
         if (request.params.sortBy) {
             const dir = request.params.sortDirection;
             query = query.sortBy(request.params.sortBy, dir === 'ASC' || dir === 'DESC' ? dir : undefined);
         } else {
             query = query.sortBy('id');
         }
-        const models = await this.models<T>(query);
+        return await query.paginate(page, perPage);
-        // @ts-ignore
-        models.pagination = new Pagination(models, page, perPage, models.totalCount);
-        return models;
     }
 
-    protected static select(...fields: string[]): Query {
+    public static select<T extends Model>(this: ModelClass<T>, ...fields: string[]): ModelQuery<T> {
-        return Query.select(this.table, ...fields);
+        return ModelQuery.select(this, ...fields);
     }
 
-    protected static update(data: { [key: string]: any }): Query {
+    public static update<T extends Model>(this: ModelClass<T>, data: { [key: string]: any }): ModelQuery<T> {
-        return Query.update(this.table, data);
+        return ModelQuery.update(this, data);
     }
 
-    protected static delete(): Query {
+    public static delete<T extends Model>(this: ModelClass<T>): ModelQuery<T> {
-        return Query.delete(this.table);
+        return ModelQuery.delete(this);
     }
 
-    protected static async models<T extends Model>(query: Query): Promise<T[]> {
+    public static getPrimaryKey(modelData: any): string {
-        const results = await query.execute();
-        const models: T[] = [];
-        const factory = this.getFactory<T>();
-        for (const result of results.results) {
-            const cachedModel = ModelCache.get(this.table, this.getPrimaryKey(result));
-            if (cachedModel && cachedModel.constructor === this) {
-                cachedModel.updateWithData(result);
-                models.push(<T>cachedModel);
-            } else {
-                models.push(factory(result));
-            }
-        }
-        // @ts-ignore
-        models.totalCount = results.foundRows;
-        return models;
-    }
-
-    protected static getPrimaryKey(modelData: any): string {
         return this.getPrimaryKeyFields().map(f => `${modelData[f]}`).join(',');
     }
 
-    protected static getPrimaryKeyFields(): string[] {
+    public static getPrimaryKeyFields(): string[] {
         return ['id'];
     }
 
@@ -82,7 +77,7 @@ export default abstract class Model {
         }
     }
 
-    private static getFactory<T extends Model>(factory?: ModelFactory<T>): ModelFactory<T> {
+    public static getFactory<T extends Model>(this: ModelClass<T>, factory?: ModelFactory<T>): ModelFactory<T> {
         if (factory === undefined) {
             factory = (<any>this).FACTORY;
             if (factory === undefined) factory = data => new (<any>this)(data);
@@ -91,8 +86,8 @@ export default abstract class Model {
     }
 
 
+    protected readonly modelClass: ModelClass<this> = <ModelClass<this>>this.constructor;
     protected readonly properties: ModelProperty<any>[] = [];
-    private readonly relations: { [p: string]: (Model | null) } = {};
     public id?: number;
     private readonly automaticIdProperty: boolean;
 
@@ -101,23 +96,23 @@ export default abstract class Model {
     public constructor(data: any, automaticIdProperty: boolean = true) {
         this.automaticIdProperty = automaticIdProperty;
         if (automaticIdProperty) {
-            this.defineProperty<number>('id', new Validator());
+            this.addProperty<number>('id', new Validator());
         }
-        this.defineProperties();
+        this.init();
         this.updateWithData(data);
     }
 
     public getPrimaryKey(): string {
-        return (<any>this.constructor).getPrimaryKey(this);
+        return this.modelClass.getPrimaryKey(this);
     }
 
-    public getPrimaryKeyFields(): string {
+    public getPrimaryKeyFields(): string[] {
-        return (<any>this.constructor).getPrimaryKeyFields();
+        return this.modelClass.getPrimaryKeyFields();
     }
 
-    protected abstract defineProperties(): void;
+    protected abstract init(): void;
 
-    protected defineProperty<T>(name: string, validator?: Validator<T> | RegExp) {
+    protected addProperty<T>(name: string, validator?: Validator<T> | RegExp) {
         if (validator === undefined) validator = new Validator();
         if (validator instanceof RegExp) {
             const regexp = validator;
@@ -162,11 +157,7 @@ export default abstract class Model {
 
         const callback = async () => {
             if (needs_full_update) {
-                this.updateWithData((await (<any>this.constructor).select().where('id', this.id!).first().execute()).results[0]);
+                this.updateWithData((await this.modelClass.select().where('id', this.id!).limit(1).execute()).results[0]);
-            }
-
-            if (!exists) {
-                this.cache();
             }
 
             await this.afterSave();
@@ -198,7 +189,7 @@ export default abstract class Model {
                     needs_full_update = true;
                 }
             }
-            let query = Query.update(this.table, data);
+            let query = this.modelClass.update(data);
             for (const indexField of this.getPrimaryKeyFields()) {
                 query = query.where(indexField, this[indexField]);
             }
@@ -222,54 +213,34 @@ export default abstract class Model {
         return needs_full_update;
     }
 
-    public static get table(): string {
-        return this.name
-                .replace(/(?:^|\.?)([A-Z])/g, (x, y) => '_' + y.toLowerCase())
-                .replace(/^_/, '')
-            + 's';
-    }
-
     public get table(): string {
-        // @ts-ignore
+        return this.modelClass.table;
-        return this.constructor.table;
     }
 
     public async exists(): Promise<boolean> {
         if (!this.id) return false;
 
-        let query = Query.select(this.table, '1');
+        let query = this.modelClass.select('1');
         for (const indexField of this.getPrimaryKeyFields()) {
             query = query.where(indexField, this[indexField]);
         }
-        query = query.first();
+        return typeof (await query.first()) !== 'undefined';
-        const result = await query.execute();
-        return result.results.length > 0;
     }
 
     public async delete(): Promise<void> {
         if (!(await this.exists())) throw new Error('This model instance doesn\'t exist in DB.');
 
-        let query = Query.delete(this.table);
+        let query = this.modelClass.delete();
         for (const indexField of this.getPrimaryKeyFields()) {
             query = query.where(indexField, this[indexField]);
         }
         await query.execute();
-        ModelCache.forget(this);
         if (this.automaticIdProperty) this.id = undefined;
     }
 
     public async validate(onlyFormat: boolean = false, connection?: Connection): Promise<void[]> {
         return await Promise.all(this.properties.map(prop => prop.validate(onlyFormat, connection)));
     }
-
-    private cache() {
-        ModelCache.cache(this);
-    }
-
-    protected relation<T extends Model>(name: string): T | null {
-        if (this.relations[name] === undefined) throw new Error('Model not loaded');
-        return <T | null>this.relations[name];
-    }
 }
 
 export interface ModelFactory<T extends Model> {
@@ -299,44 +270,4 @@ class ModelProperty<T> {
     }
 }
 
-export class ModelCache {
-    private static readonly caches: {
-        [key: string]: {
-            [key: string]: Model
-        }
-    } = {};
-
-    public static cache(instance: Model) {
-        const primaryKey = instance.getPrimaryKey();
-        if (primaryKey === undefined) throw new Error('Cannot cache an instance with an undefined primaryKey.');
-
-        let tableCache = this.caches[instance.table];
-        if (!tableCache) tableCache = this.caches[instance.table] = {};
-
-        if (!tableCache[primaryKey]) tableCache[primaryKey] = instance;
-    }
-
-    public static forget(instance: Model) {
-        const primaryKey = instance.getPrimaryKey();
-        if (primaryKey === undefined) throw new Error('Cannot forget an instance with an undefined primaryKey.');
-
-        let tableCache = this.caches[instance.table];
-        if (!tableCache) return;
-
-        if (tableCache[primaryKey]) delete tableCache[primaryKey];
-    }
-
-    public static all(table: string): {
-        [key: string]: Model
-    } | undefined {
-        return this.caches[table];
-    }
-
-    public static get(table: string, primaryKey: string): Model | undefined {
-        const tableCache = this.all(table);
-        if (!tableCache) return undefined;
-        return tableCache[primaryKey];
-    }
-}
-
 export const EMAIL_REGEX = /^[a-zA-Z0-9.!#$%&'*+\\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)+$/;

src/db/ModelQuery.ts

@@ -1,28 +1,32 @@
 import {query, QueryResult} from "./MysqlConnectionManager";
 import {Connection} from "mysql";
+import Model, {ModelClass} from "./Model";
+import Pagination from "../Pagination";
+import ModelRelation from "./ModelRelation";
 
-export default class Query {
+export default class ModelQuery<M extends Model> {
-    public static select(table: string, ...fields: string[]): Query {
+    public static select<M extends Model>(modelClass: ModelClass<M>, ...fields: string[]): ModelQuery<M> {
-        return new Query(QueryType.SELECT, table, fields.length > 0 ? fields : ['*']);
+        return new ModelQuery(QueryType.SELECT, modelClass, fields.length > 0 ? fields : ['*']);
     }
 
-    public static update(table: string, data: {
+    public static update<M extends Model>(modelClass: ModelClass<M>, data: {
         [key: string]: any
-    }): Query {
+    }): ModelQuery<M> {
         const fields = [];
         for (let key in data) {
             if (data.hasOwnProperty(key)) {
                 fields.push(new UpdateFieldValue(key, data[key], false));
             }
         }
-        return new Query(QueryType.UPDATE, table, fields);
+        return new ModelQuery(QueryType.UPDATE, modelClass, fields);
     }
 
-    public static delete(table: string): Query {
+    public static delete<M extends Model>(modelClass: ModelClass<M>): ModelQuery<M> {
-        return new Query(QueryType.DELETE, table);
+        return new ModelQuery(QueryType.DELETE, modelClass);
     }
 
     private readonly type: QueryType;
+    private readonly modelClass: ModelClass<M>;
     private readonly table: string;
     private readonly fields: (string | SelectFieldValue | UpdateFieldValue)[];
     private _leftJoin?: string;
@@ -32,11 +36,13 @@ export default class Query {
     private _offset?: number;
     private _sortBy?: string;
     private _sortDirection?: 'ASC' | 'DESC';
-    private _foundRows: boolean = false;
+    private readonly relations: string[] = [];
+    private _pivot?: string[];
 
-    private constructor(type: QueryType, table: string, fields?: (string | SelectFieldValue | UpdateFieldValue)[]) {
+    private constructor(type: QueryType, modelClass: ModelClass<M>, fields?: (string | SelectFieldValue | UpdateFieldValue)[]) {
         this.type = type;
-        this.table = table;
+        this.modelClass = modelClass;
+        this.table = modelClass.table;
         this.fields = fields || [];
     }
 
@@ -50,7 +56,7 @@ export default class Query {
         return this;
     }
 
-    public where(field: string, value: string | Date | Query | any, test: WhereTest = WhereTest.EQ, operator: WhereOperator = WhereOperator.AND): this {
+    public where(field: string, value: string | Date | ModelQuery<any> | any, test: WhereTest = WhereTest.EQ, operator: WhereOperator = WhereOperator.AND): this {
         this._where.push(new WhereFieldValue(field, value, false, test, operator));
         return this;
     }
@@ -61,25 +67,31 @@ export default class Query {
         return this;
     }
 
-    public first(): this {
-        return this.limit(1);
-    }
-
     public sortBy(field: string, direction: 'ASC' | 'DESC' = 'ASC'): this {
         this._sortBy = field;
         this._sortDirection = direction;
         return this;
     }
 
-    public withTotalRowCount(): this {
+    /**
-        this._foundRows = true;
+     * @param relation The relation field name to eagerload
+     */
+    public with(relation: string): this {
+        this.relations.push(relation);
+        return this;
+    }
+
+    public pivot(...fields: string[]): this {
+        this._pivot = fields;
         return this;
     }
 
     public toString(final: boolean = false): string {
         let query = '';
 
-        let fields = this.fields?.join(',');
+        if (this._pivot) this.fields.push(...this._pivot);
+
+        let fields = this.fields.join(',');
 
         let join = '';
         if (this._leftJoin) {
@@ -112,7 +124,7 @@ export default class Query {
 
         switch (this.type) {
             case QueryType.SELECT:
-                query = `SELECT ${this._foundRows ? 'SQL_CALC_FOUND_ROWS' : ''} ${fields} FROM ${this.table} ${join} ${where} ${orderBy} ${limit}`;
+                query = `SELECT ${fields} FROM ${this.table} ${join} ${where} ${orderBy} ${limit}`;
                 break;
             case QueryType.UPDATE:
                 query = `UPDATE ${this.table} SET ${fields} ${where} ${orderBy} ${limit}`;
@@ -140,18 +152,80 @@ export default class Query {
         return variables;
     }
 
-    public isCacheable(): boolean {
+    public async execute(connection?: Connection): Promise<QueryResult> {
-        return this.type === QueryType.SELECT && this.fields.length === 1 && this.fields[0] === '*';
+        return await query(this.build(), this.variables, connection);
     }
 
-    public async execute(connection?: Connection): Promise<QueryResult> {
+    public async get(connection?: Connection): Promise<ModelQueryResult<M>> {
-        const queryResult = await query(this.build(), this.variables, connection);
+        const queryResult = await this.execute();
-        if (this._foundRows) {
+        const models: ModelQueryResult<M> = [];
-            const foundRows = await query('SELECT FOUND_ROWS() as r', undefined, connection);
+
-            queryResult.foundRows = foundRows.results[0].r;
+        if (this._pivot) models.pivot = [];
+
+        // Eager loading init
+        const relationMap: { [p: string]: ModelRelation<any, any, any>[] } = {};
+        for (const relation of this.relations) {
+            relationMap[relation] = [];
         }
-        return queryResult;
+
+        const factory = this.modelClass.getFactory<M>();
+        for (const result of queryResult.results) {
+            const model = factory(result);
+            models.push(model);
+
+            if (this._pivot) {
+                const obj: any = {};
+                for (const field of this._pivot) {
+                    obj[field] = result[field];
+                }
+                models.pivot!.push(obj);
+            }
+
+            // Eager loading init map
+            for (const relation of this.relations) {
+                relationMap[relation].push(model[relation]);
+            }
+        }
+
+        // Eager loading execute
+        for (const relationName of this.relations) {
+            const relations = relationMap[relationName];
+            const allModels = await relations[0].eagerLoad(relations);
+            await Promise.all(relations.map(r => r.populate(allModels)));
+        }
+
+        return models;
     }
+
+    public async paginate(page: number, perPage: number, connection?: Connection): Promise<ModelQueryResult<M>> {
+        this.limit(perPage, (page - 1) * perPage);
+        const result = await this.get(connection);
+        result.pagination = new Pagination<M>(result, page, perPage, await this.count(true, connection));
+        return result;
+    }
+
+    public async first(): Promise<M | null> {
+        const models = await this.limit(1).get();
+        return models.length > 0 ? models[0] : null;
+    }
+
+    public async count(removeLimit: boolean = false, connection?: Connection): Promise<number> {
+        if (removeLimit) {
+            this._limit = undefined;
+            this._offset = undefined;
+        }
+        this._sortBy = undefined;
+        this._sortDirection = undefined;
+
+        this.fields.push('COUNT(*)');
+        let queryResult = await this.execute(connection);
+        return queryResult.results.length;
+    }
+}
+
+export interface ModelQueryResult<M extends Model> extends Array<M> {
+    pagination?: Pagination<M>;
+    pivot?: { [p: string]: any }[];
 }
 
 export enum QueryType {
@@ -187,7 +261,7 @@ class FieldValue {
     }
 
     public toString(first: boolean = true): string {
-        return `${!first ? ',' : ''}${this.field}${this.test}${this.raw || this.value instanceof Query ? this.value : (Array.isArray(this.value) ? '(?)' : '?')}`;
+        return `${!first ? ',' : ''}${this.field}${this.test}${this.raw || this.value instanceof ModelQuery ? this.value : (Array.isArray(this.value) ? '(?)' : '?')}`;
     }
 
     protected get test(): string {
@@ -195,13 +269,13 @@ class FieldValue {
     }
 
     public get variables(): any[] {
-        return this.value instanceof Query ? this.value.variables : [this.value];
+        return this.value instanceof ModelQuery ? this.value.variables : [this.value];
     }
 }
 
 class SelectFieldValue extends FieldValue {
     public toString(first: boolean = true): string {
-        return `(${this.value instanceof Query ? this.value : '?'}) AS ${this.field}`;
+        return `(${this.value instanceof ModelQuery ? this.value : '?'}) AS ${this.field}`;
     }
 }
 

src/db/ModelRelation.ts

@@ -0,0 +1,165 @@
+import ModelQuery, {ModelQueryResult, WhereTest} from "./ModelQuery";
+import Model, {ModelClass} from "./Model";
+
+export default abstract class ModelRelation<S extends Model, O extends Model, R extends O | O[] | null> {
+    protected readonly model: S;
+    protected readonly foreignModelClass: ModelClass<O>;
+    protected readonly query: ModelQuery<O>;
+    protected cachedModels?: R;
+
+    protected constructor(model: S, foreignModelClass: ModelClass<O>) {
+        this.model = model;
+        this.foreignModelClass = foreignModelClass;
+        this.query = this.foreignModelClass.select();
+    }
+
+    public abstract clone(): ModelRelation<S, O, R>;
+
+    public constraint(queryModifier: QueryModifier<O>): this {
+        queryModifier(this.query);
+        return this;
+    }
+
+    public abstract getModelID(): any;
+
+    protected abstract async compute(query: ModelQuery<O>): Promise<R>;
+
+    public async get(): Promise<R> {
+        if (this.cachedModels === undefined) {
+            this.cachedModels = await this.compute(this.query);
+        }
+        return this.cachedModels;
+    }
+
+    public abstract async eagerLoad(relations: ModelRelation<S, O, R>[]): Promise<ModelQueryResult<O>>;
+
+    public abstract async populate(models: ModelQueryResult<O>): Promise<void>;
+}
+
+export type QueryModifier<M extends Model> = (query: ModelQuery<M>) => ModelQuery<M>;
+
+export class OneModelRelation<S extends Model, O extends Model> extends ModelRelation<S, O, O | null> {
+    protected readonly dbProperties: RelationDatabaseProperties;
+
+    constructor(model: S, foreignModelClass: ModelClass<O>, dbProperties: RelationDatabaseProperties) {
+        super(model, foreignModelClass);
+        this.dbProperties = dbProperties;
+    }
+
+    public clone(): OneModelRelation<S, O> {
+        return new OneModelRelation(this.model, this.foreignModelClass, this.dbProperties);
+    }
+
+    public getModelID() {
+        return this.model[this.dbProperties.localKey];
+    }
+
+    protected async compute(query: ModelQuery<O>): Promise<O | null> {
+        this.query.where(this.dbProperties.foreignKey, this.getModelID());
+        return await query.first();
+    }
+
+    public async eagerLoad(relations: ModelRelation<S, O, O | null>[]): Promise<ModelQueryResult<O>> {
+        this.query.where(
+            this.dbProperties.foreignKey,
+            relations.map(r => r.getModelID()).filter(id => id !== null && id !== undefined),
+            WhereTest.IN
+        );
+        return await this.query.get();
+    }
+
+    public async populate(models: ModelQueryResult<O>): Promise<void> {
+        this.cachedModels = models.filter(m => m[this.dbProperties.foreignKey] === this.getModelID())[0] || null;
+    }
+
+}
+
+export class ManyModelRelation<S extends Model, O extends Model> extends ModelRelation<S, O, O[]> {
+    protected readonly dbProperties: RelationDatabaseProperties;
+
+    constructor(model: S, foreignModelClass: ModelClass<O>, dbProperties: RelationDatabaseProperties) {
+        super(model, foreignModelClass);
+        this.dbProperties = dbProperties;
+    }
+
+    public clone(): ManyModelRelation<S, O> {
+        return new ManyModelRelation<S, O>(this.model, this.foreignModelClass, this.dbProperties);
+    }
+
+    public getModelID(): any {
+        return this.model[this.dbProperties.localKey];
+    }
+
+    protected async compute(query: ModelQuery<O>): Promise<O[]> {
+        this.query.where(this.dbProperties.foreignKey, this.getModelID());
+        return await query.get();
+    }
+
+    public async eagerLoad(relations: ModelRelation<S, O, O[]>[]): Promise<ModelQueryResult<O>> {
+        this.query.where(
+            this.dbProperties.foreignKey,
+            relations.map(r => r.getModelID()).filter(id => id !== null && id !== undefined),
+            WhereTest.IN
+        );
+        return await this.query.get();
+    }
+
+    public async populate(models: ModelQueryResult<O>): Promise<void> {
+        this.cachedModels = models.filter(m => m[this.dbProperties.foreignKey] === this.getModelID);
+    }
+
+}
+
+
+export class ManyThroughModelRelation<S extends Model, O extends Model> extends ModelRelation<S, O, O[]> {
+    protected readonly dbProperties: PivotRelationDatabaseProperties;
+
+    constructor(model: S, foreignModelClass: ModelClass<O>, dbProperties: PivotRelationDatabaseProperties) {
+        super(model, foreignModelClass);
+        this.dbProperties = dbProperties;
+        this.query
+            .leftJoin(`${this.dbProperties.pivotTable} as pivot`)
+            .on(`pivot.${this.dbProperties.foreignPivotKey}`, `${this.foreignModelClass.table}.${this.dbProperties.foreignKey}`);
+    }
+
+    public clone(): ManyThroughModelRelation<S, O> {
+        return new ManyThroughModelRelation<S, O>(this.model, this.foreignModelClass, this.dbProperties);
+    }
+
+    public getModelID(): any {
+        return this.model[this.dbProperties.localKey];
+    }
+
+    protected async compute(query: ModelQuery<O>): Promise<O[]> {
+        this.query.where(`pivot.${this.dbProperties.localPivotKey}`, this.getModelID());
+        return await query.get();
+    }
+
+    public async eagerLoad(relations: ModelRelation<S, O, O[]>[]): Promise<ModelQueryResult<O>> {
+        this.query.where(
+            `pivot.${this.dbProperties.localPivotKey}`,
+            relations.map(r => r.getModelID()),
+            WhereTest.IN);
+        this.query.pivot(`pivot.${this.dbProperties.localPivotKey}`, `pivot.${this.dbProperties.foreignPivotKey}`);
+        return await this.query.get();
+    }
+
+    public async populate(models: ModelQueryResult<O>): Promise<void> {
+        const ids = models.pivot!
+            .filter(p => p[this.dbProperties.localPivotKey] === this.getModelID())
+            .map(p => p[this.dbProperties.foreignPivotKey]);
+        this.cachedModels = models.filter(m => ids.indexOf(m[this.dbProperties.foreignKey]) >= 0);
+    }
+
+}
+
+export type RelationDatabaseProperties = {
+    localKey: string;
+    foreignKey: string;
+};
+
+export type PivotRelationDatabaseProperties = RelationDatabaseProperties & {
+    pivotTable: string;
+    localPivotKey: string;
+    foreignPivotKey: string;
+};

src/db/Validator.ts

@@ -1,5 +1,5 @@
 import Model from "./Model";
-import Query, {WhereTest} from "./Query";
+import ModelQuery, {WhereTest} from "./ModelQuery";
 import {Connection} from "mysql";
 import {Type} from "../Utils";
 
@@ -174,11 +174,11 @@ export default class Validator<T> {
         return this;
     }
 
-    public unique<M extends Model>(model: M | Type<M>, foreignKey?: string, querySupplier?: () => Query): Validator<T> {
+    public unique<M extends Model>(model: M | Type<M>, foreignKey?: string, querySupplier?: () => ModelQuery<M>): Validator<T> {
         this.addStep({
             verifyStep: async (val, thingName, c) => {
                 if (!foreignKey) foreignKey = thingName;
-                let query: Query;
+                let query: ModelQuery<M>;
                 if (querySupplier) {
                     query = querySupplier().where(foreignKey, val);
                 } else {

src/models/Log.ts

@@ -11,14 +11,14 @@ export default class Log extends Model {
     private error_stack?: string;
     private created_at?: Date;
 
-    protected defineProperties(): void {
+    protected init(): void {
-        this.defineProperty<number>('level', new Validator<number>().defined());
+        this.addProperty<number>('level', new Validator<number>().defined());
-        this.defineProperty<string>('message', new Validator<string>().defined().between(0, 65535));
+        this.addProperty<string>('message', new Validator<string>().defined().between(0, 65535));
-        this.defineProperty<Buffer>('log_id', new Validator<Buffer>().acceptUndefined().length(16));
+        this.addProperty<Buffer>('log_id', new Validator<Buffer>().acceptUndefined().length(16));
-        this.defineProperty<string>('error_name', new Validator<string>().acceptUndefined().between(0, 128));
+        this.addProperty<string>('error_name', new Validator<string>().acceptUndefined().between(0, 128));
-        this.defineProperty<string>('error_message', new Validator<string>().acceptUndefined().between(0, 512));
+        this.addProperty<string>('error_message', new Validator<string>().acceptUndefined().between(0, 512));
-        this.defineProperty<string>('error_stack', new Validator<string>().acceptUndefined().between(0, 65535));
+        this.addProperty<string>('error_stack', new Validator<string>().acceptUndefined().between(0, 65535));
-        this.defineProperty<Date>('created_at', new Validator<Date>());
+        this.addProperty<Date>('created_at', new Validator<Date>());
     }
 
     public getLevel(): LogLevelKeys {

test/Model.test.ts

@@ -8,10 +8,10 @@ class FakeDummyModel extends Model {
     public date?: Date;
     public date_default?: Date;
 
-    protected defineProperties(): void {
+    protected init(): void {
-        this.defineProperty<string>('name', new Validator().acceptUndefined().between(3, 256));
+        this.addProperty<string>('name', new Validator().acceptUndefined().between(3, 256));
-        this.defineProperty<Date>('date', new Validator());
+        this.addProperty<Date>('date', new Validator());
-        this.defineProperty<Date>('date_default', new Validator());
+        this.addProperty<Date>('date_default', new Validator());
     }
 }
 
@@ -54,7 +54,7 @@ describe('Model', () => {
         expect(instance.date?.getTime()).toBeCloseTo(date.getTime(), -4);
         expect(instance.date_default).toBeDefined();
 
-        instance = await FakeDummyModel.getById('1');
+        instance = await FakeDummyModel.getById(1);
         expect(instance).toBeDefined();
         expect(instance!.id).toBe(1);
         expect(instance!.name).toBe('name1');