Fixed issue: Added a call to the getValue method (laravel#48652)

* Fixed issue: Added a call to the getValue method. Without this, raw SQL queries in conditions throw an exception.

* Added check to prevent call on types other than Expression

* Added new test cases for the modified method

* Refactored the variable names

* Fixed a StyleCI issue

* Update Grammar.php

---------

Co-authored-by: Bojan Lozo <bojanlo@maestralsolutions.com>
Co-authored-by: Taylor Otwell <taylor@laravel.com>

src/Illuminate/Database/Query/Grammars/Grammar.php

@@ -2,6 +2,7 @@
 
 namespace Illuminate\Database\Query\Grammars;
 
+use Illuminate\Contracts\Database\Query\Expression;
 use Illuminate\Database\Concerns\CompilesJsonPaths;
 use Illuminate\Database\Grammar as BaseGrammar;
 use Illuminate\Database\Query\Builder;
@@ -246,7 +247,7 @@ protected function concatenateWhereClauses($query, $sql)
      */
     protected function whereRaw(Builder $query, $where)
     {
-        return $where['sql'];
+        return $where['sql'] instanceof Expression ? $where['sql']->getValue($this) : $where['sql'];
     }
 
     /**

tests/Database/DatabaseQueryGrammarTest.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace Illuminate\Tests\Database;
+
+use Illuminate\Database\Query\Builder;
+use Illuminate\Database\Query\Expression;
+use Illuminate\Database\Query\Grammars\Grammar;
+use Mockery as m;
+use PHPUnit\Framework\TestCase;
+use ReflectionClass;
+
+class DatabaseQueryGrammarTest extends TestCase
+{
+    protected function tearDown(): void
+    {
+        m::close();
+    }
+
+    public function testWhereRawReturnsStringWhenExpressionPassed()
+    {
+        $builder = m::mock(Builder::class);
+        $grammar = new Grammar;
+        $reflection = new ReflectionClass($grammar);
+        $method = $reflection->getMethod('whereRaw');
+        $expressionArray = ['sql' => new Expression('select * from "users"')];
+
+        $rawQuery = $method->invoke($grammar, $builder, $expressionArray);
+
+        $this->assertSame('select * from "users"', $rawQuery);
+    }
+
+    public function testWhereRawReturnsStringWhenStringPassed()
+    {
+        $builder = m::mock(Builder::class);
+        $grammar = new Grammar;
+        $reflection = new ReflectionClass($grammar);
+        $method = $reflection->getMethod('whereRaw');
+        $stringArray = ['sql' => 'select * from "users"'];
+
+        $rawQuery = $method->invoke($grammar, $builder, $stringArray);
+
+        $this->assertSame('select * from "users"', $rawQuery);
+    }
+}