public String wrapperPlaceholder(String fieldName) {
        int pos = fieldList.indexOf(fieldName);
        String type = fieldTypeList.get(pos);

        if (StringUtils.contains(type.toLowerCase(), DEAL_CHAR_KEY)) {
            AbstractTableInfo.FieldExtraInfo fieldExtraInfo = fieldExtraInfoList.get(pos);
            int charLength = fieldExtraInfo == null ? 0 : fieldExtraInfo.getLength();
            if (charLength > 0) {
                return String.format(RPAD_FORMAT, charLength);
            }
        }
        return SQL_DEFAULT_PLACEHOLDER;
    }
char type is wrapped with rpad
@param fieldName
@return
oracle/oracle-sink/src/main/java/com/dtstack/flink/sql/sink/oracle/OracleDialect.java