code: protected void registerColumnType(String columnType, int jdbcType) {
          columnTypeMatchers.add(new ColumnTypeMatcher(columnType));
          jdbcTypes.put(columnType, jdbcType);
      }
docs: Subclasses register a typename for the given type code.
  
  @param columnType the database column type
  @param jdbcType <tt>java.sql.Types</tt> typecode