title: ROracle connect and pull utf8 characters
body: <p>I am connecting to an Oracle database from R using ROracle.  The problem is for every special utf-8 character it returns a question mark.  Some Chinese values returns a solid string of question marks.  I believe this is relevant because I haven't found any other question on this site (or others) that answers this for the package ROracle.
  Some questions that were the most promising include an answer for MySQL: <a href="https://stackoverflow.com/questions/12869778/fetching-utf-8-text-from-mysql-in-r-returns">Fetching UTF-8 text from MySQL in R returns &quot;????&quot;</a>  but I was unable to make this work for ROracle.  This site also provided some useful information <a href="https://docs.oracle.com/cd/E17952_01/mysql-5.5-en/charset-connection.html" rel="nofollow noreferrer">https://docs.oracle.com/cd/E17952_01/mysql-5.5-en/charset-connection.html</a> Before I was using RODBC and was easily able to configure the uft-8 encoding.  </p>
  
  <p>Here is some sample code...  I am sorry that unless you have an Oracle database with utf-8 characters it may be impossible to duplicate...  I also changed the host number and the sid for data privacy reasons... </p>
  
  <pre><code>library(ROracle)
  drv &lt;- dbDriver("Oracle")
  # Create the connection string
  host &lt;- "10.00.000.86"
  port &lt;- 1521
  sid &lt;- "f110"
  connect.string &lt;- paste(
    "(DESCRIPTION=",
    "(ADDRESS=(PROTOCOL=tcp)(HOST=", host, ")(PORT=", port, "))",
    "(CONNECT_DATA=(SID=", sid, ")))", sep = "")
  
  con &lt;- dbConnect(drv, username = "XXXXXXXXX",
                   password = "xxxxxxxxx",dbname=connect.string)
  
  my.table &lt;- dbReadTable(con, "DASH_D_PROJECT_INFO")
  
  my.table[40, 1:3]  
  
     PROJECT_ID DATE_INPUT PROJECT_NAME
      211625   2012-07-01  ??????, ?????????????????? ????? ??????, 1869?1917 [????? 3]
  </code></pre>
  
  <p>Any help is appreciated.  I have read the entire documentation of the ROracle packages, and it seemed to have a solution for writing utf-8 characters, but not for reading them.  </p>