Document that union queries can be built using eloquent builders (#43949)

Author: axlon

src/Illuminate/Database/Query/Builder.php

@@ -2438,7 +2438,7 @@ protected function removeExistingOrdersFor($column)
     /**
      * Add a union statement to the query.
      *
-     * @param  \Illuminate\Database\Query\Builder|\Closure  $query
+     * @param  \Closure|\Illuminate\Database\Query\Builder|\Illuminate\Database\Eloquent\Builder  $query
      * @param  bool  $all
      * @return $this
      */
@@ -2458,7 +2458,7 @@ public function union($query, $all = false)
     /**
      * Add a union all statement to the query.
      *
-     * @param  \Illuminate\Database\Query\Builder|\Closure  $query
+     * @param  \Closure|\Illuminate\Database\Query\Builder|\Illuminate\Database\Eloquent\Builder  $query
      * @return $this
      */
     public function unionAll($query)

tests/Database/DatabaseQueryBuilderTest.php

@@ -993,6 +993,12 @@ public function testUnions()
         $builder->union($this->getSqlServerBuilder()->select('name')->from('users')->where('id', '=', 2));
         $this->assertEquals($expectedSql, $builder->toSql());
         $this->assertEquals([0 => 1, 1 => 2], $builder->getBindings());
+
+        $builder = $this->getBuilder();
+        $eloquentBuilder = new EloquentBuilder($this->getBuilder());
+        $builder->select('*')->from('users')->where('id', '=', 1)->union($eloquentBuilder->select('*')->from('users')->where('id', '=', 2));
+        $this->assertSame('(select * from "users" where "id" = ?) union (select * from "users" where "id" = ?)', $builder->toSql());
+        $this->assertEquals([0 => 1, 1 => 2], $builder->getBindings());
     }
 
     public function testUnionAlls()
@@ -1009,6 +1015,13 @@ public function testUnionAlls()
         $builder->unionAll($this->getBuilder()->select('*')->from('users')->where('id', '=', 2));
         $this->assertEquals($expectedSql, $builder->toSql());
         $this->assertEquals([0 => 1, 1 => 2], $builder->getBindings());
+
+        $builder = $this->getBuilder();
+        $eloquentBuilder = new EloquentBuilder($this->getBuilder());
+        $builder->select('*')->from('users')->where('id', '=', 1);
+        $builder->unionAll($eloquentBuilder->select('*')->from('users')->where('id', '=', 2));
+        $this->assertSame('(select * from "users" where "id" = ?) union all (select * from "users" where "id" = ?)', $builder->toSql());
+        $this->assertEquals([0 => 1, 1 => 2], $builder->getBindings());
     }
 
     public function testMultipleUnions()