In order to provide support for roles being assigned to multiple users, the role_user table is needed. This would mean that a role could only belong to a single user. Remember, since a role can belong to many users, we cannot simply place a user_id column on the roles table. This table is used as an intermediate table linking the users and roles. The role_user table is derived from the alphabetical order of the related model names and contains user_id and role_id columns. To define this relationship, three database tables are needed: users, roles, and role_user. So, a user has many roles and a role has many users.

For example, a user may be assigned the role of 'Author' and 'Editor' however, those roles may also be assigned to other users as well. An example of a many-to-many relationship is a user that has many roles and those roles are also shared by other users in the application. Many-to-many relations are slightly more complicated than hasOne and hasMany relationships. The fifth argument is the local key, while the sixth argument is the local key of the intermediate model: The fourth argument is the name of the foreign key on the final model. The third argument is the name of the foreign key on the intermediate model. If you would like to customize the keys of the relationship, you may pass them as the third and fourth arguments to the hasManyThrough method.

Typical Eloquent foreign key conventions will be used when performing the relationship's queries. After finding the relevant environment IDs, they are used to query the Deployment model's table. To retrieve these models, Eloquent inspects the project_id column on the intermediate Environment model's table. Though the Deployment model's table does not contain a project_id column, the hasManyThrough relation provides access to a project's deployments via $project->deployments. The first argument passed to the hasManyThrough method is the name of the final model we wish to access, while the second argument is the name of the intermediate model. This closure will be responsible for adding additional publish date constraints to the relationship query: In addition, a closure will be provided as the second argument to the ofMany method. To accomplish this, we must pass an array to the ofMany method that contains the sortable columns which determine the latest price. In addition, if two prices have the same published date, we will prefer the price with the greatest ID. So, in summary, we need to retrieve the latest published pricing where the published date is not in the future. In addition, new pricing data for the product may be able to be published in advance to take effect at a future date via a published_at column. For example, A Product model may have many associated Price models that are retained in the system even after new pricing is published. It is possible to construct more advanced 'has one of many' relationships. Because PostgreSQL does not support executing the MAX function against UUID columns, it is not currently possible to use one-of-many relationships in combination with PostgreSQL UUID columns. Eloquent makes managing and working with these relationships easy, and supports a variety of common relationships: For example, a blog post may have many comments or an order could be related to the user who placed it. Counting Related Models On Morph To Relationshipsĭatabase tables are often related to one another.Defining Custom Intermediate Table Models.Filtering Queries Via Intermediate Table Columns.

Laravel eloquent find with relation