Eloquent relationships huiga jinsi tables za database zinavyohusiana, zikibainishwa kama methods kwenye models. Laravel huunga mkono aina zote za kawaida za relationship — one-to-many, many-to-many, one-to-one, na zaidi — zikikupa ufikiaji nadhifu na unaolenga object wa data inayohusiana.
{
{
->(::);
}
}
{
{
->(::);
}
}
->posts;
->author;
->()->(, )->();
Relationship ya kawaida zaidi: mzazi hasMany watoto, na kila mtoto belongsTo mzazi. Kufikia relationship kama property hurudisha model(s) inayohusiana.
class Post extends Model {
public function tags() { // posts and tags — many-to-many
return $this->belongsToMany(Tag::class); // uses a pivot table (post_tag)
}
}
$post->tags; // the post's tags
$post->tags()->attach($tagId); // add an association
$post->tags()->detach($tagId); // remove
$post->tags()->sync([1, 2, 3]); // set exactly these
Many-to-many hutumia pivot table (inayosimamiwa kiotomatiki), na attach/detach/sync kusimamia mahusiano.
$this->hasOne(Profile::class); // one-to-one
$this->hasManyThrough(...); // has-many through an intermediate model
$this->morphMany(Comment::class, 'commentable'); // POLYMORPHIC (comments on posts OR videos)
// ❌ N+1: a query per post to get each author
$posts = Post::all();
foreach ($posts as $post) { echo $post->author->name; }
// ✅ eager load with with() — fetches authors in ONE extra query
$posts = Post::with('author')->get();
Tumia with() ku-eager-load relationships na kuzuia tatizo la N+1 query.
Eloquent relationships ni muhimu kwa kufanya kazi na data ya kihusiano (relational) katika Laravel — karibu kila programu ina entities zinazohusiana (users na posts, posts na tags, orders na items), hivyo kuelewa jinsi ya kubainisha na kutumia relationships ni maarifa ya msingi ya kila siku.
Kujua aina za relationship na lini kutumia kila moja — hasMany/belongsTo kwa one-to-many (ya kawaida zaidi), belongsToMany kwa many-to-many (na pivot table na attach/detach/sync), hasOne kwa one-to-one, na polymorphic relations kwa mahusiano yanayoweza kubadilika — ni muhimu kwa kuiga data yoyote isiyo ya kawaida na ni mojawapo ya vipengele vyenye nguvu na nadhifu zaidi vya Eloquent.
Relationships hukupa ufikiaji wa kueleweka na unaolenga object wa data inayohusiana ($user->posts, $post->author) bila kuandika joins kwa mkono, jambo ambalo ni faida kubwa ya tija.
Kwa umuhimu mkubwa, kuelewa eager loading na with() ili kuzuia tatizo la N+1 query (ambapo kufikia relationships ndani ya loop husababisha query kwa kila record — tatizo kubwa la utendaji) ni muhimu, kwa kuwa relationships hufanya matatizo ya N+1 kuwa rahisi kuanzisha.
Kuimudu Eloquent relationships — kuzibainisha, kufikia data inayohusiana, na ku-eager-load kuepuka N+1 — ni maarifa ya msingi na yanayotumika mara kwa mara yanayotegemeza uigaji bora wa data na utendaji katika programu za Laravel.