belongsToMany(Employee::class) Īs we may have noticed, when we use the many-to-many relationship, we are always supposed to have an intermediate table. To define the inverse relationship of the belongsToMany we simply use the same method but on the child method now, with the parent as an argument. Like all other methods, we can overwrite the foreign and local keys of the belongsToMany method. Since our Tenant model can be associated with many Rent models, we want to easily retrieve the latest or oldest related model of the relationships.Ī convenient way of doing this is combining the hasOne and ofMany methods: public function latestRent() ) Now we have all the rent of a tenant, but what do we do when we know the rent and want to figure out to whom it belongs? We can make use of the belongsTo property: belongsTo(Tenant::class) Īnd now we can get the tenant easily: $tenant = Rent::find(1)->tenant įor the belongsTo method, we can also overwrite the foreign and local keys as we did before. In this case, our previous relationship has flaws, and we can fix them: hasMany(Rent::class) īefore we call the method to get the rents, a good thing to know is that relationships serve as query builders, so we can further add constraints (like rent in between dates, min payment, etc.) and chain them to get our desired result: $rents = Tenant::find(10)->rent()->where('payment', '>', 500)->first() Īnd like the previous relationship, we can overwrite the foreign and local keys by passing additional arguments: return $this->hasMany(Rent::class, "foreign_key") return $this->hasMany(Rent::class, "foreign_key", "local_key") It is unlikely that our Tenant will have only one Rent bill because it is a recurring payment, therefore, he will have multiple payments. Like the previous relationship, this will define relationships between a single-parent model and multiple children models. With this line of code, we get the tenant’s rent with the id 10 if it exists. Now that we have defined the one-to-one relationship between the models, we can use it easily, like this: $rent = Tenant::find(10)->rent We can overwrite this with a third argument in the hasOne method, such that it will match another key: return $this->hasOne(Rent::class, "custom_key", "other_key") By default, it will look to match tenant_id with the id key of the Tenant record. We can easily overwrite it like with an additional argument to the hasOne method: return $this- >hasOne(Rent::class, "custom_key") Įloquent also assumes that there is a match between the defined foreign key and the primary key of the parent (Tenant model). hasOne(Rent::class) īecause eloquent determines the foreign key relationship based on the parent model name (Tenant in this case), the Rent model assumes that there exists a tenant_id foreign key. To see this in action, we have to create two models with their own migration: php artisan make:model TenantĪt this point, we have two models, one being the Tenant and the other being their Rent. Database schema with three tables and a joint table representing a polymorphic relationship One-To-One Relationshipīeing the first basic relation Laravel offers, they associate two tables in a way such that one row from the first table is correlated with only one row from the other table. We can easily create a simple one-to-many relation in Laravel to help us out, such as when we need to query the products, we can do it by using the Product model. This comes with issues of its own, as you do not want to query each and every single table. Therefore, splitting the database into multiple tables makes sense from a business point of view. Take, for example, a store whose inventory contains a variety of articles, each in its own category. Laravel makes it seamless to interact and manage database relationships using object-oriented syntax in Eloquent.Īlong with these definitions, Laravel introduces more relationships, namely: Namely, students and the courses they are enrolled in. many-to-many – Multiple records in a table are associated with multiple records in another table.one-to-many – One record is associated with multiple records in another table.For example, a person and a social security number. one-to-one – One record in a table is associated with one, and only one, in another table.There are three types of database relationships in practice: This helps you organize and structure data effortlessly allowing for superior readability and handling of data. When working with tables in a relational database, we can characterize relationships as connections between tables.
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