syntax error, unexpected '' (T_ENCAPSED_AND_WHITESPACE), expecting '-' or identifier code example

Example: Parse error: syntax error, unexpected '' (T_ENCAPSED_AND_WHITESPACE), expecting '-' or identifier (T_STRING) or variable (T_VARIABLE) or number (T_NUM_STRING)

echo $sqlupdate1 = "UPDATE table SET commodity_quantity=$qty WHERE user='".$rows['user']."' ";