TypeORM Entity

2023-08-13 18:32:34

TypeORM Entity

Entity

Entity is a class that maps to a database table when using SQL database(or collection when using MongoDB).

https://orkhan.gitbook.io/typeorm/docs/entities

@Entity()

依赖注入 / 注解 / 修饰器

You can create an entity by defining a new class and mark it with @Entity():

// step 1, 创建一个实体

import {

  Entity,

  PrimaryGeneratedColumn,

  Column,

} from "typeorm";



@Entity()

export class User {

    @PrimaryGeneratedColumn()

    id: number;

    @Column()

    firstName: string;

    @Column()

    lastName: string;

    @Column()

    isActive: boolean;

}

register entity

Each entity must be registered in your connection options:

// step 2, 注册一个实体

import {createConnection, Connection} from "typeorm";

import {User} from "./entity/User";



const connection: Connection = await createConnection({

    type: "mysql",

    host: "localhost",

    port: 3306,

    username: "test",

    password: "test",

    database: "test",

    entities: [User]

});

you can specify the whole directory with all entities inside - and all of them will be loaded:

// step 2, 注册一组实体

import {createConnection, Connection} from "typeorm";



const connection: Connection = await createConnection({

    type: "mysql",

    host: "localhost",

    port: 3306,

    username: "test",

    password: "test",

    database: "test",

    entities: ["entity/*.js"], // * 通配符

});

alias 别名

If you want to use an alternative table name for the User entity you can specify it in @Entity: @Entity("my_users").

If you want to set a base prefix for all database tables in your application you can specify entityPrefix in connection options.

connection options

https://orkhan.gitbook.io/typeorm/docs/connection-options

mysql / mariadb connection options

postgres / cockroachdb connection options

sqlite connection options

cordova connection options

react-native connection options

nativescript connection options

mssql connection options

mongodb connection options

sql.js connection options

expo connection options

Common connection options

type - Database type. (required)

"mysql", "postgres", "cockroachdb", "mariadb", "sqlite", "cordova", "nativescript", "oracle", "mssql", "mongodb", "sqljs", "react-native".

https://orkhan.gitbook.io/typeorm/docs/connection-options#common-connection-options

PostgreSQL

postgres

https://orkhan.gitbook.io/typeorm/docs/connection-options#postgres-cockroachdb-connection-options

Decorators reference

https://orkhan.gitbook.io/typeorm/docs/decorator-reference#entity

create a database table named "users".

@Entity("users")

export class User {

  //...

}

specify some additional entity options:

name - table name. If not specified, then table name is generated from entity class name.
database - database name in selected DB server.
schema - schema name.
engine - database engine to be set during table creation (works only in some databases).
synchronize - entities marked with false are skipped from schema updates.
orderBy - specifies default ordering for entities when using find operations and QueryBuilder.



@Entity({

    name: "users",

    engine: "MyISAM",

    database: 'example_dev',

    schema: 'schema_with_best_tables',

    synchronize: false,

    orderBy: {

        name: "ASC",

        id: "DESC"

    }

})

export class User {

  //...

}

refs

PostgreSQL

PostgreSQL is a powerful, open source object-relational database system with over 30 years of active development that has earned it a strong reputation for reliability, feature robustness, and performance.

https://www.postgresql.org/

https://www.postgresql.org/docs/12/index.html