Change to getFieldNames()

If query returns no rows then I wouldn't get field names. this way I do.

Author: sclubricants

system/Database/BaseBuilder.php

@@ -2128,9 +2128,9 @@ public function fromQuery($query, $columns = null): BaseBuilder
      */
     protected function fieldsFromQuery(string $sql): array
     {
-        $query = $this->db->query('SELECT * FROM (' . $sql . ') _u_ LIMIT 1')->getResultArray();
+        $fields = $this->db->query('SELECT * FROM (' . $sql . ') _u_ LIMIT 1')->getFieldNames();
 
-        return array_keys(current($query));
+        return $fields;
     }
 
     /**

system/Database/OCI8/Builder.php

@@ -519,8 +519,8 @@ protected function _deleteBatch(string $table, array $keys, array $values): stri
      */
     protected function fieldsFromQuery(string $sql): array
     {
-        $query = $this->db->query('SELECT * FROM (' . $sql . ') "_u_" WHERE ROWNUM = 1')->getResultArray();
+        $fields = $this->db->query('SELECT * FROM (' . $sql . ') "_u_" WHERE ROWNUM = 1')->getFieldNames();
 
-        return array_keys(current($query));
+        return $fields;
     }
 }

system/Database/SQLSRV/Builder.php

@@ -770,8 +770,8 @@ protected function _upsertBatch(string $table, array $keys, array $values): stri
      */
     protected function fieldsFromQuery(string $sql): array
     {
-        $query = $this->db->query('SELECT TOP 1 * FROM (' . $sql . ') _u_')->getResultArray();
+        $fields = $this->db->query('SELECT TOP 1 * FROM (' . $sql . ') _u_')->getFieldNames();
 
-        return array_keys(current($query));
+        return $fields;
     }
 }