Now, let's imagine we want to retrieve ActivityFeed instances and eager load the parentable parent models for each ActivityFeed instance.Have you ever listened to a brilliant speaker and felt captivated by the music of their speech, the poetry of their words and the resonance of their voice? Then they probably have that magical combination that we call eloquence. Additionally, let's assume that Photo models "have many" Tag models and Post models "have many" Comment models. We will assume the ActivityFeed model defines a "morph to" relationship named parentable that allows us to retrieve the parent Photo or Post model for a given ActivityFeed instance. In this example, let's assume that Photo and Post models may create ActivityFeed models. If you would like to eager load a "morph to" relationship, as well as related model counts for the various entities that may be returned by that relationship, you may utilize the with method in combination with the morphTo relationship's morphWithCount method. We can summarize the relationship's table structure like so:Ĭounting Related Models On Morph To Relationships 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. Return $this -> throughEnvironments () -> hasDeployments () 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. Eloquent makes managing and working with these relationships easy, and supports a variety of common relationships:īecause 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. 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.Ordering Queries Via Intermediate Table Columns.Filtering Queries Via Intermediate Table Columns.
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