How to Generate Entities from an Existing Database¶

When starting work on a brand new project that uses a database, two different situations comes naturally. In most cases, the database model is designed and built from scratch. Sometimes, however, you’ll start with an existing and probably unchangeable database model. Fortunately, Doctrine comes with a bunch of tools to help generate model classes from your existing database.

This tutorial assumes you’re using a simple blog application with the following two tables: blog_post and blog_comment. A comment record is linked to a post record thanks to a foreign key constraint.

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CREATE TABLE `blog_post` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `title` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
  `content` longtext COLLATE utf8_unicode_ci NOT NULL,
  `created_at` datetime NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

CREATE TABLE `blog_comment` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `post_id` bigint(20) NOT NULL,
  `author` varchar(20) COLLATE utf8_unicode_ci NOT NULL,
  `content` longtext COLLATE utf8_unicode_ci NOT NULL,
  `created_at` datetime NOT NULL,
  PRIMARY KEY (`id`),
  KEY `blog_comment_post_id_idx` (`post_id`),
  CONSTRAINT `blog_post_id` FOREIGN KEY (`post_id`) REFERENCES `blog_post` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

Before diving into the recipe, be sure your database connection parameters are correctly setup in the .env file.

The first step towards building entity classes from an existing database is to ask Doctrine to introspect the database and generate the corresponding metadata files. Metadata files describe the entity class to generate based on table fields.

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$ php bin/console doctrine:mapping:import App\\Entity annotation --path=src/Entity

This command line tool asks Doctrine to introspect the database and generate new PHP classes with annotation metadata into src/Entity. This generates two files: BlogPost.php and BlogComment.php.

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$ php bin/console doctrine:mapping:import App\\Entity xml --path=config/doctrine

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// generates getter/setter methods
$ php bin/console make:entity --regenerate App