framework/db/DataReader.php
public function rewind()
    {
        if ($this->_index < 0) {
            $this->_row = $this->_statement->fetch();
            $this->_index = 0;
        } else {
            throw new InvalidCallException('DataReader cannot rewind. It is a forward-only reader.');
        }
    }
public function rewind()
    {
        if ($this->_index < 0) {
            $this->_row = $this->_statement->fetch();
            $this->_index = 0;
        } else {
            throw new InvalidCallException('DataReader cannot rewind. It is a forward-only reader.');
        }
    }
Resets the iterator to the initial state.
This method is required by the interface [[\Iterator]].
@throws InvalidCallException if this method is invoked twice