docs: public final int getJdbcType()
      {
          switch (this.fieldSource)
          {
              case SOURCE_FIELD :
                  return this.getFieldRef().getJdbcType().getType();
              case SOURCE_NULL :
                  return java.sql.Types.NULL;
              case SOURCE_VALUE :
                  return java.sql.Types.VARCHAR;
              default :
                  return java.sql.Types.NULL;
          }
      }