public String getNString(String columnName) throws SQLException {
        throw new SQLFeatureNotSupportedException(resBundle.handleGetObject("jdbcrowsetimpl.featnotsupp").toString());
    }
Retrieves the value of the designated column in the current row
of this <code>ResultSet</code> object as
a <code>String</code> in the Java programming language.
It is intended for use when
accessing  <code>NCHAR</code>,<code>NVARCHAR</code>
and <code>LONGNVARCHAR</code> columns.

@param columnName the SQL name of the column
@return the column value; if the value is SQL <code>NULL</code>, the
value returned is <code>null</code>
@exception SQLException if a database access error occurs
@since 1.6
src/main/java/org/replicadb/rowset/sun/rowset/JdbcRowSetImpl.java