feat: select() supports RawSql

Author: kenjis

system/Database/BaseBuilder.php

@@ -371,6 +371,12 @@ public function select($select = '*', ?bool $escape = null)
             $escape = $this->db->protectIdentifiers;
         }
 
+        if ($select instanceof RawSql) {
+            $this->QBSelect[] = $select;
+
+            return $this;
+        }
+
         foreach ($select as $val) {
             $val = trim($val);
 
@@ -2339,6 +2345,8 @@ protected function compileSelect($selectOverride = false): string
 
             if (empty($this->QBSelect)) {
                 $sql .= '*';
+            } elseif ($this->QBSelect[0] instanceof RawSql) {
+                $sql .= (string) $this->QBSelect[0];
             } else {
                 // Cycle through the "select" portion of the query and prep each column name.
                 // The reason we protect identifiers here rather than in the select() function

tests/system/Database/Builder/SelectTest.php

@@ -13,6 +13,7 @@
 
 use CodeIgniter\Database\BaseBuilder;
 use CodeIgniter\Database\Exceptions\DataException;
+use CodeIgniter\Database\RawSql;
 use CodeIgniter\Database\SQLSRV\Builder as SQLSRVBuilder;
 use CodeIgniter\Test\CIUnitTestCase;
 use CodeIgniter\Test\Mock\MockConnection;
@@ -95,6 +96,20 @@ public function testSelectWorksWithComplexSelects()
         $this->assertSame($expected, str_replace("\n", ' ', $builder->getCompiledSelect()));
     }
 
+    /**
+     * @see https://github.com/codeigniter4/CodeIgniter4/issues/4355
+     */
+    public function testSelectWorksWithRawSql()
+    {
+        $builder = new BaseBuilder('users', $this->db);
+
+        $sql = 'REGEXP_SUBSTR(ral_anno,"[0-9]{1,2}([,.][0-9]{1,3})([,.][0-9]{1,3})") AS ral';
+        $builder->select(new RawSql($sql));
+
+        $expected = 'SELECT ' . $sql . ' FROM "users"';
+        $this->assertSame($expected, str_replace("\n", ' ', $builder->getCompiledSelect()));
+    }
+
     public function testSelectMinWithNoAlias()
     {
         $builder = new BaseBuilder('invoices', $this->db);