public void updateAsciiStream(String columnName, InputStream x, int length) throws SQLException {
        updateAsciiStream(findColumn(columnName), x, length);
    }
Updates the designated column with an ascii stream value.
The <code>updateXXX</code> methods are used to update column values in the
current row or the insert row.  The <code>updateXXX</code> methods do not
update the underlying database; instead the <code>updateRow</code> or
<code>insertRow</code> methods are called to update the database.

@param columnName the name of the column
@param x the new column value
@param length the length of the stream
@throws SQLException if a database access error occurs
src/main/java/org/replicadb/rowset/sun/rowset/JdbcRowSetImpl.java