1. 根据列表批量修改

void secretKeySequence(@Param("list")List<IndustrialShareDto> list);

<update id="secretKeySequence">
   update cloud_industrial_set
       set `index` =
      case
    <foreach collection="list" item="item">
        when id = #{item.id} then #{item.index}
    </foreach>
    end
    where id in(
    <foreach collection="list" item="item" separator=",">
        #{item.id}
    </foreach>
    )
</update>

2. 小于号的处理

 select username from t where id <![CDATA[ <= ]]> #{id}

3. 大小写重复列的问题

出现在 3.0.5 版本独有的问题，当返回值是 resultType = java.util.Map 时，会有两个列

<select id="findDataShowSet" resultType="java.util.Map">
     select sqltext,customid
       from datashowset
      where showname = #{showName}
      order by id
     offset 0 rows fetch next 1 rows only
</select>

查找原因：FastResultSetHandler.loadMappedAndUnmappedColumnNames()

protected void loadMappedAndUnmappedColumnNames(ResultSet rs, ResultMap resultMap, List<String> mappedColumnNames, List<String> unmappedColumnNames) throws SQLException {
  mappedColumnNames.clear();
  unmappedColumnNames.clear();
  final ResultSetMetaData rsmd = rs.getMetaData();
  final int columnCount = rsmd.getColumnCount();
  final Set<String> mappedColumns = resultMap.getMappedColumns();
  for (int i = 1; i <= columnCount; i++) {
    final String columnName = configuration.isUseColumnLabel() ? rsmd.getColumnLabel(i) : rsmd.getColumnName(i);
    //获取大写
    final String upperColumnName = columnName.toUpperCase(Locale.ENGLISH);
    //大写小写都存了一遍
    if (mappedColumns.contains(upperColumnName)) {
      mappedColumnNames.add(upperColumnName);
      mappedColumnNames.add(columnName);
    } else {
      unmappedColumnNames.add(upperColumnName);
      unmappedColumnNames.add(columnName);
    }
  }
}

要么换版本，要么手动去掉

Set<String> upperKeys = new HashSet<>();
dataList.forEach(map -> {
    upperKeys.addAll(map.keySet());
});
dataList.forEach(
        map -> {
            for(String key : upperKeys){
                map.remove(key.toUpperCase(Locale.ENGLISH));
            }
        }
);