belongsTo

Usage

A belongsTo relationship is a many-to-one relationship. For instance, a Post may belong to a User.

// Post.cfc
component extends="quick.models.BaseEntity" accessors="true" {

    function user() {
       return belongsTo( "User" );
    }

}

The first value passed to belongsTo is a WireBox mapping to the related entity.

Quick determines the foreign key of the relationship based on the entity name and key values. In this case, the Post entity is assumed to have a userId foreign key. You can override this by passing a foreign key in as the second argument:

return belongsTo( "User", "FK_userID" );

If your parent entity does not use id as its primary key, or you wish to join the child entity to a different column, you may pass a third argument to the belongsTo method specifying your parent table's custom key.

return belongsTo( "User", "FK_userID", "relatedPostId" );

The inverse of belongsTo is hasMany or hasOne.

// User.cfc
component extends="quick.models.BaseEntity" accessors="true" {

    function posts() {
        return hasMany( "Post" );
    }

    function latestPost() {
        // remember, relationships are just queries!
        return hasOne( "Post" ).orderBy( "createdDate", "desc" );
    }

}

Updating

To update a belongsTo relationship, use the associate method. associate takes the entity to associate as the only argument.

var post = getInstance( "Post" ).findOrFail(1);
var user = getInstance( "User" ).findOrFail(1);
post.user().associate( user );
post.save();

associate does not automatically save the entity. Make sure to call save when you are ready to persist your changes to the database.

Removing

To remove a belongsTo relationship, use the dissociate method.

var post = getInstance( "Post" ).findOrFail(1);
post.user().dissociate();
post.save();

dissociate does not automatically save the entity. Make sure to call save when you are ready to persist your changes to the database.

Relationship Setter

You can also influence the associated entities by calling "set" & relationshipName and passing in an entity or key value.

var post = getInstance( "Post" ).first();
post.setAuthor( 1 );

After executing this code, the post would be updated in the database to be associated with the user with an id of 1.

withDefault

BelongsTo relationships can be configured to return a default entity if no entity is found. This is done by calling withDefault on the relationship object.

// Post.cfc
component extends="quick.models.BaseEntity" accessors="true" {

    function user() {
       return belongsTo( "User" ).withDefault();
    }

}

Called this way will return a new unloaded entity with no data. You can also specify any default attributes data by passing in a struct of data to withDefault.

// Post.cfc
component extends="quick.models.BaseEntity" accessors="true" {

    function user() {
       return belongsTo( "User" ).withDefault( {
           "firstName": "Guest",
           "lastName": "Author"
       } );
    }

}

Signature

Returns a BelongsTo relationship between this entity and the entity defined by relationName.

Visualizer

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