DDC-551: Consider adding ability to specify additional join conditions on a @JoinTable / @JoinColumn #680

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admin · 2026-01-22T12:46:32+01:00

admin commented

2026-01-22 12:46:32 +01:00

Originally created by @doctrinebot on GitHub (Apr 28, 2010).

Originally assigned to: @asm89 on GitHub.

Jira issue originally created by user mjh_ca:

Per discussion with beberlei and romanb in #doctrine-dev yesterday, opening this ticket as a "feature request" to support migrating legacy schemas with a special many-to-many mapping to Doctrine.

Consider the following schema:

CREATE TABLE categories (
    category*id BIGINT UNSIGNED NOT NULL AUTO*INCREMENT,
    content_type ENUM('posts', 'videos'),
    /** ... **/
    PRIMARY KEY (category_id)
) ENGINE=InnoDB;

CREATE TABLE content*category*association (
    content_id BIGINT UNSIGNED NOT NULL,
    category_id BIGINT UNSIGNED NOT NULL,
    content_type ENUM('posts', 'videos'),
    PRIMARY KEY (content*id, category_id, content*type),
    FOREIGN KEY (category*id, content_type) REFERENCES categories(category_id, content*type) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB;

CREATE TABLE posts (
    post*id BIGINT UNSIGNED NOT NULL AUTO*INCREMENT,
    /** ... **/
    PRIMARY KEY (post_id)
) ENGINE=InnoDB;

CREATE TABLE videos (
    video*id BIGINT UNSIGNED NOT NULL AUTO*INCREMENT,
    /** ... **/
) ENGINE=InnoDB;

There is a Many-To-Many relationship between each of the posts and videos table (via the content_category_association table) to the categories table. The difference from a standard many-to-many relationship is there is an extra column in the association table (content_type) which must be included in the join condition to return correct results. Since both the videos and posts table have their own autonumber primary keys, a join against the association table must include an extra condition (i.e. INNER JOIN ... ON ... AND content_category_association.content_type = 'posts').

Perhaps you could allow passing of additional properties to @JoinTable / joinColumns to specify the additional join condition .. i.e.:

/*** @Entity **/
class Video
{
  /****
   * @ManyToMany(targetEntity="Category")
   * @JoinTable(name="content*category*association",
   *      joinColumns={@JoinColumn(name="content*id", referencedColumnName="video*id")},
   *      inverseJoinColumns={@JoinColumn(name="category*id", referencedColumnName="video*id")},
   *      extraJoinTerms={@JoinTerm(content_type="video")}
   *      )
   */
  private $categories;

  // ...
}

/*** @Entity **/
class Category
{
    // ...
}

Certainly this schema is not ideal from a pure OO perspective. Class inheritance with a discriminator column may have been a better way to do this, thereby allowing a globally unique "content_id" for all types of content, negating the need for the extra column in the association table. However, it would nonetheless be helpful to have this additional capability within Doctrine to avoid having to re-factor such a legacy schema.

Originally created by @doctrinebot on GitHub (Apr 28, 2010). Originally assigned to: @asm89 on GitHub. Jira issue originally created by user mjh_ca: Per discussion with beberlei and romanb in #doctrine-dev yesterday, opening this ticket as a "feature request" to support migrating legacy schemas with a special many-to-many mapping to Doctrine. Consider the following schema: ``` CREATE TABLE categories ( category*id BIGINT UNSIGNED NOT NULL AUTO*INCREMENT, content_type ENUM('posts', 'videos'), /** ... **/ PRIMARY KEY (category_id) ) ENGINE=InnoDB; CREATE TABLE content*category*association ( content_id BIGINT UNSIGNED NOT NULL, category_id BIGINT UNSIGNED NOT NULL, content_type ENUM('posts', 'videos'), PRIMARY KEY (content*id, category_id, content*type), FOREIGN KEY (category*id, content_type) REFERENCES categories(category_id, content*type) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB; CREATE TABLE posts ( post*id BIGINT UNSIGNED NOT NULL AUTO*INCREMENT, /** ... **/ PRIMARY KEY (post_id) ) ENGINE=InnoDB; CREATE TABLE videos ( video*id BIGINT UNSIGNED NOT NULL AUTO*INCREMENT, /** ... **/ ) ENGINE=InnoDB; ``` There is a Many-To-Many relationship between each of the posts and videos table (via the content_category_association table) to the categories table. The difference from a standard many-to-many relationship is there is an extra column in the association table (content_type) which must be included in the join condition to return correct results. Since both the videos and posts table have their own autonumber primary keys, a join against the association table must include an extra condition (i.e. INNER JOIN ... ON ... AND content_category_association.content_type = 'posts'). Perhaps you could allow passing of additional properties to @JoinTable / joinColumns to specify the additional join condition .. i.e.: ``` /*** @Entity **/ class Video { /**** * @ManyToMany(targetEntity="Category") * @JoinTable(name="content*category*association", * joinColumns={@JoinColumn(name="content*id", referencedColumnName="video*id")}, * inverseJoinColumns={@JoinColumn(name="category*id", referencedColumnName="video*id")}, * extraJoinTerms={@JoinTerm(content_type="video")} * ) */ private $categories; // ... } /*** @Entity **/ class Category { // ... } ``` Certainly this schema is not ideal from a pure OO perspective. Class inheritance with a discriminator column may have been a better way to do this, thereby allowing a globally unique "content_id" for all types of content, negating the need for the extra column in the association table. However, it would nonetheless be helpful to have this additional capability within Doctrine to avoid having to re-factor such a legacy schema.

admin added the Improvement label 2026-01-22 12:46:32 +01:00

admin referenced this issue

2026-01-22 16:00:25 +01:00

[PR #680] [CLOSED] [wip] better reverse engineers the mapping metadata from a database #8548

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Reference: doctrine/archived-orm#680