[11.x] Added useCascadeTruncate method for PostgresGrammar

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

@@ -38,6 +38,13 @@ class PostgresGrammar extends Grammar
         '~', '&', '|', '#', '<<', '>>', '<<=', '>>=',
     ];
 
+    /**
+     * Indicates if the cascade option should be used when truncating.
+     *
+     * @var bool
+     */
+    protected static $cascadeTruncate = true;
+
     /**
      * Compile a basic where clause.
      *
@@ -653,7 +660,7 @@ protected function compileDeleteWithJoinsOrLimit(Builder $query)
      */
     public function compileTruncate(Builder $query)
     {
-        return ['truncate '.$this->wrapTable($query->from).' restart identity cascade' => []];
+        return ['truncate '.$this->wrapTable($query->from).' restart identity'.(static::$cascadeTruncate ? ' cascade' : '') => []];
     }
 
     /**
@@ -802,4 +809,15 @@ public static function customOperators(array $operators)
             array_merge(static::$customOperators, array_filter(array_filter($operators, 'is_string')))
         );
     }
+
+    /**
+     * Enable or disable the "cascade" option when compiling the truncate statement.
+     *
+     * @param  bool  $value
+     * @return void
+     */
+    public static function cascadeOnTrucate(bool $value = true)
+    {
+        static::$cascadeTruncate = $value;
+    }
 }

tests/Database/DatabasePostgresQueryGrammarTest.php

@@ -3,6 +3,7 @@
 namespace Illuminate\Tests\Database;
 
 use Illuminate\Database\Connection;
+use Illuminate\Database\Query\Builder;
 use Illuminate\Database\Query\Grammars\PostgresGrammar;
 use Mockery as m;
 use PHPUnit\Framework\TestCase;
@@ -47,4 +48,27 @@ public function testCustomOperators()
         $this->assertNotContains(1, $operators);
         $this->assertSame(array_unique($operators), $operators);
     }
+
+    public function testCompileTruncate()
+    {
+        $postgres = new PostgresGrammar;
+        $builder = m::mock(Builder::class);
+        $builder->from = 'users';
+
+        $this->assertEquals([
+            'truncate "users" restart identity cascade' => [],
+        ], $postgres->compileTruncate($builder));
+
+        PostgresGrammar::cascadeOnTrucate(false);
+
+        $this->assertEquals([
+            'truncate "users" restart identity' => [],
+        ], $postgres->compileTruncate($builder));
+
+        PostgresGrammar::cascadeOnTrucate();
+
+        $this->assertEquals([
+            'truncate "users" restart identity cascade' => [],
+        ], $postgres->compileTruncate($builder));
+    }
 }