Adding has() functionality for hasMany and hasOne relations

src/Jenssegers/Eloquent/Model.php

 <?php namespace Jenssegers\Eloquent;
 
-use Illuminate\Database\Eloquent\Relations\HasOne;
-use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Database\Eloquent\Relations\MorphOne;
 use Illuminate\Database\Eloquent\Relations\MorphMany;
 use Illuminate\Database\Eloquent\Relations\Relation;
+use Jenssegers\Mongodb\Relations\HasOne;
+use Jenssegers\Mongodb\Relations\HasMany;
 use Jenssegers\Mongodb\Relations\BelongsTo;
 use Jenssegers\Mongodb\Relations\BelongsToMany;
 use Jenssegers\Mongodb\Relations\MorphTo;

src/Jenssegers/Mongodb/Eloquent/Builder.php

 <?php namespace Jenssegers\Mongodb\Eloquent;
 
 use MongoCursor;
+use Illuminate\Database\Eloquent\Relations\Relation;
+use Illuminate\Database\Eloquent\Builder as EloquentBuilder;
 
-class Builder extends \Illuminate\Database\Eloquent\Builder {
+class Builder extends EloquentBuilder {
 
     /**
      * The methods that should be returned from query builder.
@@ -14,6 +16,56 @@ class Builder extends \Illuminate\Database\Eloquent\Builder {
         'count', 'min', 'max', 'avg', 'sum', 'exists', 'push', 'pull'
     );
 
+    /**
+     * Add the "has" condition where clause to the query.
+     *
+     * @param  \Illuminate\Database\Eloquent\Builder  $hasQuery
+     * @param  \Illuminate\Database\Eloquent\Relations\Relation  $relation
+     * @param  string  $operator
+     * @param  int  $count
+     * @param  string  $boolean
+     * @return \Illuminate\Database\Eloquent\Builder
+     */
+    protected function addHasWhere(EloquentBuilder $hasQuery, Relation $relation, $operator, $count, $boolean)
+    {
+        $query = $hasQuery->getQuery();
+
+        // Get the number of related objects for each possible parent.
+        $relationCount = array_count_values($query->lists($relation->getHasCompareKey()));
+
+        // Remove unwanted related objects based on the operator and count.
+        $relationCount = array_filter($relationCount, function($counted) use ($count, $operator)
+        {
+            // If we are comparing to 0, we always need all results.
+            if ($count == 0) return true;
+
+            switch ($operator)
+            {
+                case '>=':
+                case '<':
+                    return $counted >= $count;
+                case '>':
+                case '<=':
+                    return $counted > $count;
+                case '=':
+                case '!=':
+                    return $counted == $count;
+            }
+        });
+
+        // If the operator is <, <= or !=, we will use whereNotIn.
+        $not = in_array($operator, array('<', '<=', '!='));
+
+        // If we are comparing to 0, we need an additional $not flip.
+        if ($count == 0) $not = !$not;
+
+        // All related ids.
+        $relatedIds = array_keys($relationCount);
+
+        // Add whereIn to the query.
+        return $this->whereIn($this->model->getKeyName(), $relatedIds, $boolean, $not);
+    }
+
     /**
      * Create a raw database expression.
      *

src/Jenssegers/Mongodb/Relations/HasMany.php

+<?php namespace Jenssegers\Mongodb\Relations;
+
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Collection;
+use Illuminate\Database\Eloquent\Relations\HasMany as EloquentHasMany;
+
+class HasMany extends EloquentHasMany {
+
+    /**
+     * Add the constraints for a relationship count query.
+     *
+     * @param  \Illuminate\Database\Eloquent\Builder  $query
+     * @param  \Illuminate\Database\Eloquent\Builder  $parent
+     * @return \Illuminate\Database\Eloquent\Builder
+     */
+    public function getRelationCountQuery(Builder $query, Builder $parent)
+    {
+        $foreignKey = $this->getHasCompareKey();
+
+        return $query->select($this->getHasCompareKey())->where($this->getHasCompareKey(), 'exists', true);
+    }
+
+}

src/Jenssegers/Mongodb/Relations/HasOne.php

+<?php namespace Jenssegers\Mongodb\Relations;
+
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Collection;
+use Illuminate\Database\Eloquent\Relations\HasOne as EloquentHasOne;
+
+class HasOne extends EloquentHasOne {
+
+    /**
+     * Add the constraints for a relationship count query.
+     *
+     * @param  \Illuminate\Database\Eloquent\Builder  $query
+     * @param  \Illuminate\Database\Eloquent\Builder  $parent
+     * @return \Illuminate\Database\Eloquent\Builder
+     */
+    public function getRelationCountQuery(Builder $query, Builder $parent)
+    {
+        $foreignKey = $this->getHasCompareKey();
+
+        return $query->select($this->getHasCompareKey())->where($this->getHasCompareKey(), 'exists', true);
+    }
+
+}

tests/RelationsTest.php

@@ -303,4 +303,79 @@ class RelationsTest extends TestCase {
         $this->assertInstanceOf('Client', $relations['imageable']);
     }
 
+    public function testHasManyHas()
+    {
+        $author1 = User::create(array('name' => 'George R. R. Martin'));
+        $author1->books()->create(array('title' => 'A Game of Thrones', 'rating' => 5));
+        $author1->books()->create(array('title' => 'A Clash of Kings', 'rating' => 5));
+        $author2 = User::create(array('name' => 'John Doe'));
+        $author2->books()->create(array('title' => 'My book', 'rating' => 2));
+        User::create(array('name' => 'Anonymous author'));
+        Book::create(array('title' => 'Anonymous book', 'rating' => 1));
+
+        $authors = User::has('books')->get();
+        $this->assertCount(2, $authors);
+        $this->assertEquals('George R. R. Martin', $authors[0]->name);
+        $this->assertEquals('John Doe', $authors[1]->name);
+
+        $authors = User::has('books', '>', 1)->get();
+        $this->assertCount(1, $authors);
+
+        $authors = User::has('books', '<', 5)->get();
+        $this->assertCount(3, $authors);
+
+        $authors = User::has('books', '>=', 2)->get();
+        $this->assertCount(1, $authors);
+
+        $authors = User::has('books', '<=', 1)->get();
+        $this->assertCount(2, $authors);
+
+        $authors = User::has('books', '=', 2)->get();
+        $this->assertCount(1, $authors);
+
+        $authors = User::has('books', '!=', 2)->get();
+        $this->assertCount(2, $authors);
+
+        $authors = User::has('books', '=', 0)->get();
+        $this->assertCount(1, $authors);
+
+        $authors = User::has('books', '!=', 0)->get();
+        $this->assertCount(2, $authors);
+
+        $authors = User::whereHas('books', function($query)
+        {
+            $query->where('rating', 5);
+
+        })->get();
+        $this->assertCount(1, $authors);
+
+        $authors = User::whereHas('books', function($query)
+        {
+            $query->where('rating', '<', 5);
+
+        })->get();
+        $this->assertCount(1, $authors);
+    }
+
+    public function testHasOneHas()
+    {
+        $user1 = User::create(array('name' => 'John Doe'));
+        $user1->role()->create(array('title' => 'admin'));
+        $user2 = User::create(array('name' => 'Jane Doe'));
+        $user2->role()->create(array('title' => 'reseller'));
+        User::create(array('name' => 'Mark Moe'));
+        Role::create(array('title' => 'Customer'));
+
+        $users = User::has('role')->get();
+        $this->assertCount(2, $users);
+        $this->assertEquals('John Doe', $users[0]->name);
+        $this->assertEquals('Jane Doe', $users[1]->name);
+
+        $users = User::has('role', '=', 0)->get();
+        $this->assertCount(1, $users);
+
+        $users = User::has('role', '!=', 0)->get();
+        $this->assertCount(2, $users);
+    }
+
 }