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itemscope itemtype=https://schema.org/BreadcrumbList><li class=breadcrumbs__item><a aria-label="Home page" class=breadcrumbs__link href=/><svg viewBox="0 0 24 24" class=breadcrumbHomeIcon_xK9p><path d="M10 19v-5h4v5c0 .55.45 1 1 1h3c.55 0 1-.45 1-1v-7h1.7c.46 0 .68-.57.33-.87L12.67 3.6c-.38-.34-.96-.34-1.34 0l-8.36 7.53c-.34.3-.13.87.33.87H5v7c0 .55.45 1 1 1h3c.55 0 1-.45 1-1z" fill=currentColor /></svg></a><li itemscope itemprop=itemListElement itemtype=https://schema.org/ListItem class=breadcrumbs__item><a class=breadcrumbs__link itemprop=item href=/docs/advanced>Advanced Features</a><meta itemprop=position content=1></ul></nav>Version: 6.4<div class="tocCollapsible_ETCw theme-doc-toc-mobile tocMobile_ITEo"><button type=button class="clean-btn tocCollapsibleButton_TO0P">On this page</button></div><div class="theme-doc-markdown markdown"><header><h1>Defining Entities via EntitySchema</h1></header>With <code>EntitySchema</code> helper we define the schema programmatically. <div class="language-ts codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockTitle_Ktv7>./entities/Book.ts</div><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-ts codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv>export interface Book extends CustomBaseEntity { title: string; author: Author; publisher: Publisher; tags: Collection<BookTag>; } // The second type argument is optional, and should be used only with custom // base entities, not with the `BaseEntity` class exported from `@mikro-orm/core`. export const schema = new EntitySchema<Book, CustomBaseEntity>({ // name should be used only with interfaces name: 'Book', // if we use actual class, we need this instead: // class: Book, extends: CustomBaseEntitySchema, // only if we extend custom base entity properties: { title: { type: 'string' }, author: { kind: 'm:1', entity: 'Author', inversedBy: 'books' }, publisher: { kind: 'm:1', entity: 'Publisher', inversedBy: 'books' }, tags: { kind: 'm:n', entity: 'BookTag', inversedBy: 'books', fixedOrder: true }, }, }); </code></pre><div class=buttonGroup__atx><button type=button aria-label="Copy code to clipboard" title=Copy class=clean-btn><svg viewBox="0 0 24 24" class=copyButtonIcon_y97N><path fill=currentColor d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"/></svg><svg viewBox="0 0 24 24" class=copyButtonSuccessIcon_LjdS><path fill=currentColor d=M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z /></svg></button></div></div></div> When creating new entity instances, you will need to use <code>em.create()</code> method that will create instance of internally created class. <div class="language-ts codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-ts codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv>// instance of internal Author class const author = em.create<Author>('Author', { name: 'name', email: 'email' }); await em.flush(); </code></pre><div class=buttonGroup__atx><button type=button aria-label="Copy code to clipboard" title=Copy class=clean-btn><svg viewBox="0 0 24 24" class=copyButtonIcon_y97N><path fill=currentColor d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"/></svg><svg viewBox="0 0 24 24" class=copyButtonSuccessIcon_LjdS><path fill=currentColor d=M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z /></svg></button></div></div></div> <blockquote> Using this approach, metadata caching is automatically disabled as it is not needed. </blockquote> <h2 class="anchor anchorWithStickyNavbar_LWe7" id=using-custom-entity-classes>Using custom entity classes<a href=#using-custom-entity-classes class=hash-link aria-label="Direct link to Using custom entity classes" title="Direct link to Using custom entity classes"></a></h2> You can optionally use custom class for entity instances. <div class="language-ts codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockTitle_Ktv7>./entities/Author.ts</div><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-ts codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv>export class Author extends CustomBaseEntity { name: string; email: string; age?: number; termsAccepted?: boolean; identities?: string[]; born?: string; books = new Collection<Book>(this); favouriteBook?: Book; version?: number; constructor(name: string, email: string) { super(); this.name = name; this.email = email; } } export const schema = new EntitySchema<Author, CustomBaseEntity>({ class: Author, extends: CustomBaseEntitySchema, properties: { name: { type: 'string' }, email: { type: 'string', unique: true }, age: { type: 'number', nullable: true }, termsAccepted: { type: 'boolean', default: 0, onCreate: () => false }, identities: { type: 'string[]', nullable: true }, born: { type: DateType, nullable: true, length: 3 }, books: { kind: '1:m', entity: () => 'Book', mappedBy: book => book.author }, favouriteBook: { kind: 'm:1', type: 'Book' }, version: { type: 'number', persist: false }, }, }); </code></pre><div class=buttonGroup__atx><button type=button aria-label="Copy code to clipboard" title=Copy class=clean-btn><svg viewBox="0 0 24 24" class=copyButtonIcon_y97N><path fill=currentColor d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"/></svg><svg viewBox="0 0 24 24" class=copyButtonSuccessIcon_LjdS><path fill=currentColor d=M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z /></svg></button></div></div></div> Then you can use the entity class as usual: <div class="language-ts codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-ts codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv>const author = new Author('name', 'email'); await em.persist(author).flush(); </code></pre><div class=buttonGroup__atx><button type=button aria-label="Copy code to clipboard" title=Copy class=clean-btn><svg viewBox="0 0 24 24" class=copyButtonIcon_y97N><path fill=currentColor d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"/></svg><svg viewBox="0 0 24 24" class=copyButtonSuccessIcon_LjdS><path fill=currentColor d=M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z /></svg></button></div></div></div> <h2 class="anchor anchorWithStickyNavbar_LWe7" id=using-custom-base-entity>Using custom base entity<a href=#using-custom-base-entity class=hash-link aria-label="Direct link to Using custom base entity" title="Direct link to Using custom base entity"></a></h2> Do not forget that base entities needs to be discovered just like normal entities. <div class="language-ts codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockTitle_Ktv7>./entities/BaseEntity.ts</div><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-ts codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv>export interface CustomBaseEntity { id: number; createdAt: Date; updatedAt: Date; } export const schema = new EntitySchema<CustomBaseEntity>({ name: 'CustomBaseEntity', abstract: true, properties: { id: { type: 'number', primary: true }, createdAt: { type: 'Date', onCreate: () => new Date(), nullable: true }, updatedAt: { type: 'Date', onCreate: () => new Date(), onUpdate: () => new Date(), nullable: true }, }, }); </code></pre><div class=buttonGroup__atx><button type=button aria-label="Copy code to clipboard" title=Copy class=clean-btn><svg viewBox="0 0 24 24" class=copyButtonIcon_y97N><path fill=currentColor d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"/></svg><svg viewBox="0 0 24 24" class=copyButtonSuccessIcon_LjdS><path fill=currentColor d=M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z /></svg></button></div></div></div> <h2 class="anchor anchorWithStickyNavbar_LWe7" id=configuration-reference>Configuration Reference<a href=#configuration-reference class=hash-link aria-label="Direct link to Configuration Reference" title="Direct link to Configuration Reference"></a></h2> The parameter of <code>EntitySchema</code> requires to provide either <code>name</code> or <code>class</code> parameters. When using <code>class</code>, <code>extends</code> will be automatically inferred. You can optionally pass these additional parameters: <div class="language-ts codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-ts codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv>name: string; class: Constructor<T>; extends: string; tableName: string; // alias for `collection: string` properties: { [K in keyof T & string]: EntityProperty<T[K]> }; indexes: { properties: string | string[]; name?: string; type?: string }[]; uniques: { properties: string | string[]; name?: string }[]; repository: () => Constructor<EntityRepository<T>>; hooks: Partial<Record<keyof typeof EventType, ((string & keyof T) | NonNullable<EventSubscriber[keyof EventSubscriber]>)[]>>; abstract: boolean; </code></pre><div class=buttonGroup__atx><button type=button aria-label="Copy code to clipboard" title=Copy class=clean-btn><svg viewBox="0 0 24 24" class=copyButtonIcon_y97N><path fill=currentColor d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"/></svg><svg viewBox="0 0 24 24" class=copyButtonSuccessIcon_LjdS><path fill=currentColor d=M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z /></svg></button></div></div></div> Every property then needs to contain a type specification - one of <code>type</code> or <code>entity</code> options. Here are some examples of various property types: <div class="language-ts codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-ts codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv>export enum MyEnum { LOCAL = 'local', GLOBAL = 'global', } export const schema = new EntitySchema<FooBar>({ name: 'FooBar', tableName: 'tbl_foo_bar', indexes: [{ name: 'idx1', properties: 'name' }], uniques: [{ name: 'unq1', properties: ['name', 'email'] }], repository: () => FooBarRepository, properties: { id: { type: 'number', primary: true }, name: { type: 'string' }, baz: { kind: '1:1', entity: 'FooBaz', orphanRemoval: true, nullable: true }, fooBar: { kind: '1:1', entity: 'FooBar', nullable: true }, publisher: { kind: 'm:1', entity: 'Publisher', inversedBy: 'books' }, books: { kind: '1:m', entity: () => 'Book', mappedBy: book => book.author }, tags: { kind: 'm:n', entity: 'BookTag', inversedBy: 'books', fixedOrder: true }, version: { type: 'Date', version: true, length: 0 }, type: { enum: true, items: () => MyEnum, default: MyEnum.LOCAL }, }, }); </code></pre><div class=buttonGroup__atx><button type=button aria-label="Copy code to clipboard" title=Copy class=clean-btn><svg viewBox="0 0 24 24" class=copyButtonIcon_y97N><path fill=currentColor d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"/></svg><svg viewBox="0 0 24 24" class=copyButtonSuccessIcon_LjdS><path fill=currentColor d=M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z /></svg></button></div></div></div> <blockquote> As a value for <code>type</code> you can also use one of <code>String</code>/<code>Number</code>/<code>Boolean</code>/<code>Date</code>. </blockquote> <h2 class="anchor anchorWithStickyNavbar_LWe7" id=mongodb-example>MongoDB example<a href=#mongodb-example class=hash-link aria-label="Direct link to MongoDB example" title="Direct link to MongoDB example"></a></h2> <div class="language-ts codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-ts codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv>export class BookTag { _id!: ObjectId; id!: string; name: string; books = new Collection<Book>(this); constructor(name: string) { this.name = name; } } export const schema = new EntitySchema<BookTag>({ class: BookTag, properties: { _id: { type: 'ObjectId', primary: true }, id: { type: 'string', serializedPrimaryKey: true }, name: { type: 'string' }, books: { kind: 'm:n', entity: () => Book, mappedBy: book => book.tags }, }, }); </code></pre><div class=buttonGroup__atx><button type=button aria-label="Copy code to clipboard" title=Copy class=clean-btn><svg viewBox="0 0 24 24" class=copyButtonIcon_y97N><path fill=currentColor d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"/></svg><svg viewBox="0 0 24 24" class=copyButtonSuccessIcon_LjdS><path fill=currentColor d=M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z /></svg></button></div></div></div> <h2 class="anchor anchorWithStickyNavbar_LWe7" id=hooks-example>Hooks example<a href=#hooks-example class=hash-link aria-label="Direct link to Hooks example" title="Direct link to Hooks example"></a></h2> Entity hooks can be defined either as a property name, or as a function. When defined as a function, the <code>this</code> argument will be the entity instance. Arrow functions can be used if desired, and the entity will be available at args.entity. See <a href=/docs/events>Events and Lifecycle Hooks</a> section for more details on <code>EventArgs</code>. <div class="language-ts codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-ts codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv>export class BookTag { _id!: ObjectId; id!: string; name: string; books = new Collection<Book>(this); constructor(name: string) { this.name = name; } // Defined on an entity class. beforeCreate() { this.version = 1; } beforeUpdate() { this.version++; } } // Defined outside of entity class - this bound to entity instance function beforeUpdate() { this.version++; } // Defined outside, this available via args. const beforeUpdate2 = (args: EventArgs) => args.entity.version++; export const schema = new EntitySchema({ class: BookTag, hooks: { beforeCreate: ['beforeCreate'], // Instance method beforeUpdate: ['beforeUpdate', beforeUpdate, beforeUpdate2] // Instance method, normal function, arrow function }, properties: { _id: { type: 'ObjectId', primary: true }, id: { type: 'string', serializedPrimaryKey: true }, name: { type: 'string' }, books: { kind: 'm:n', entity: () => Book, mappedBy: book => book.tags }, }, }); </code></pre><div class=buttonGroup__atx><button type=button aria-label="Copy code to clipboard" title=Copy class=clean-btn><svg viewBox="0 0 24 24" class=copyButtonIcon_y97N><path fill=currentColor d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"/></svg><svg viewBox="0 0 24 24" class=copyButtonSuccessIcon_LjdS><path fill=currentColor d=M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z /></svg></button></div></div></div></div><footer class="theme-doc-footer docusaurus-mt-lg"><div class="row margin-top--sm theme-doc-footer-edit-meta-row"><div class=col><a href=https://github.com/mikro-orm/mikro-orm/edit/master/docs/versioned_docs/version-6.4/entity-schema.md target=_blank rel="noopener noreferrer" class=theme-edit-this-page><svg fill=currentColor height=20 width=20 viewBox="0 0 40 40" class=iconEdit_Z9Sw aria-hidden=true><g><path d="m34.5 11.7l-3 3.1-6.3-6.3 3.1-3q0.5-0.5 1.2-0.5t1.1 0.5l3.9 3.9q0.5 0.4 0.5 1.1t-0.5 1.2z m-29.5 17.1l18.4-18.5 6.3 6.3-18.4 18.4h-6.3v-6.2z"/></g></svg>Edit this page</a></div><div class="col lastUpdated_JAkA">Last updated on <time datetime=2024-11-11T06:40:23.000Z itemprop=dateModified>Nov 11, 2024</time> by Martin Adámek</div></div></footer></article><nav class="pagination-nav docusaurus-mt-lg" aria-label="Docs pages"><a class="pagination-nav__link pagination-nav__link--prev" href=/docs/embeddables><div class=pagination-nav__sublabel>Previous</div><div class=pagination-nav__label>Embeddables</div></a><a class="pagination-nav__link pagination-nav__link--next" href=/docs/json-properties><div class=pagination-nav__sublabel>Next</div><div class=pagination-nav__label>Using JSON properties</div></a></nav></div></div><div class="col col--3"><div class="tableOfContents_bqdL thin-scrollbar theme-doc-toc-desktop"><ul class="table-of-contents table-of-contents__left-border"><li><a href=#using-custom-entity-classes class="table-of-contents__link toc-highlight">Using custom entity classes</a><li><a href=#using-custom-base-entity class="table-of-contents__link toc-highlight">Using custom base entity</a><li><a href=#configuration-reference class="table-of-contents__link toc-highlight">Configuration Reference</a><li><a href=#mongodb-example class="table-of-contents__link toc-highlight">MongoDB example</a><li><a href=#hooks-example class="table-of-contents__link toc-highlight">Hooks example</a></ul></div></div></div></div></main></div></div></div><footer class="footer footer--dark"><div class=container><div class="row footer__links"><div class="col footer__col"><h4 class=footer__title>Docs</h4><ul class=footer__items><li class=footer__item><a class=footer__link-item href=/docs/quick-start>Quick Start</a><li class=footer__item><a class=footer__link-item href=/docs/guide>Getting Started</a><li class=footer__item><a class=footer__link-item href=/docs/upgrading-v5-to-v6>Migration from v5 to v6</a><li class=footer__item><a class=footer__link-item href=/docs/5.9/installation>Version 5.9 docs</a></ul></div><div class="col footer__col"><h4 class=footer__title>Community</h4><ul class=footer__items><li class=footer__item><a href=https://discord.gg/w8bjxFHS7X target=_blank rel="noopener noreferrer" class=footer__link-item>Discord</a><li class=footer__item><a href=https://join.slack.com/t/mikroorm/shared_invite/enQtNTM1ODYzMzM4MDk3LWM4ZDExMjU5ZDhmNjA2MmM3MWMwZmExNjhhNDdiYTMwNWM0MGY5ZTE3ZjkyZTMzOWExNDgyYmMzNDE1NDI5NjA target=_blank rel="noopener noreferrer" class=footer__link-item>Slack</a><li class=footer__item><a href="https://stackoverflow.com/questions/ask?tags=mikro-orm" target=_blank rel="noopener noreferrer" class=footer__link-item>Stack Overflow</a></ul></div><div class="col footer__col"><h4 class=footer__title>Social</h4><ul class=footer__items><li class=footer__item><a class=footer__link-item href=/blog>Blog</a><li class=footer__item><a href=https://twitter.com/MikroORM target=_blank rel="noopener noreferrer" class=footer__link-item>Twitter</a><li class=footer__item><a href=https://github.com/mikro-orm/mikro-orm target=_blank rel="noopener noreferrer" class=footer__link-item>GitHub</a><li class=footer__item><iframe src="https://ghbtns.com/github-btn.html?user=B4nan&type=sponsor" frameborder=0 scrolling=0 width=150 height=30 title="Sponsor B4nan"></iframe></ul></div></div><div class=text--center><div class=margin-bottom--sm><img class=footer__logo alt=MikroORM src=/img/logo-header.svg></div>Copyright © 2018-2024 Martin Adámek. 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