original_string: public function select($columns)
      {
          if (is_array($columns)) {
              $this->columns = $columns;
          } elseif ($columns === '*') {
              $this->columns = ['*'];
          }
          return $this;
      }
code: public function select($columns)
      {
          if (is_array($columns)) {
              $this->columns = $columns;
          } elseif ($columns === '*') {
              $this->columns = ['*'];
          }
          return $this;
      }
code_tokens: public function select ( $ columns ) { if ( is_array ( $ columns ) ) { $ this -> columns = $ columns ; } elseif ( $ columns === '*' ) { $ this -> columns = [ '*' ] ; } return $ this ; }
docstring: Sets the columns to be selected
  
  @param array $columns Columns to select
  @return object Database instance
docstring_tokens: Sets the columns to be selected