Difference between polymorphic and Standard relationship in Laravel

In Laravel, Eloquent relationships provide a convenient way to interact with related database tables. Both polymorphic relationships and standard (non-polymorphic) relationships fall under the umbrella of Eloquent relationships, but they serve different purposes.

Standard (Non-Polymorphic) Relationships:

• In standard relationships, you have a straightforward connection between two models using foreign key constraints.
• For example, you might have a Post model and a Comment model, where each comment belongs to a post. In this case, you would have a posts table and a comments table. The comments table would have a foreign key column like post_id that references the id column in the posts table.
• You define the relationship in the models, and Eloquent provides methods to query and retrieve related data.

Post Model:

// Post Modelclass Post extends Model{    public function comments()    {        return $this->hasMany(Comment::class);    }}

Comment Model:

// Comment Modelclass Comment extends Model{    public function post()    {        return $this->belongsTo(Post::class);    }}

Usage:

// Get comments for a post$comments = Post::find(1)->comments;

Polymorphic Relationships:

• Polymorphic relationships allow a model to belong to more than one type of other model on a single association.
• This is useful when you have entities that can be associated with multiple types of other entities without having to create a separate table for each relationship.
• In a polymorphic relationship, the related model's type and ID are stored in columns on the calling model's table.
• For example, you might have a Comment model that can belong to both Post and Video models. In this case, you would have a comments table with commentable_type and commentable_id columns.

Comment Model:

// Comment Modelclass Comment extends Model{    public function commentable()    {        return $this->morphTo();    }}

Post Model:

// Post Modelclass Post extends Model{    public function comments()    {        return $this->morphMany(Comment::class, 'commentable');    }}

Video Model:

// Video Modelclass Video extends Model{    public function comments()    {        return $this->morphMany(Comment::class, 'commentable');    }}

Usage:

// Get comments for a post$comments = Post::find(1)->comments;// Get comments for a video$comments = Video::find(1)->comments;

In summary, standard relationships are used when there's a direct one-to-many or many-to-one connection between models, while polymorphic relationships are used when a model can belong to multiple types of other models on a single association.