我的cassandra表列用小写，如下所示

CREATE TABLE model_family_by_id(
  model_family_id int PRIMARY KEY,
  model_family text,
  create_date   date,
  last_update_date date,
  model_family_name text
);

我的Dataframe模式是这样的

root
               |-- MODEL_FAMILY_ID: decimal(38,10) (nullable = true)
               |-- MODEL_FAMILY: string (nullable = true)
               |-- CREATE_DATE: timestamp (nullable = true)
               |-- LAST_UPDATE_DATE: timestamp (nullable = true)
               |-- MODEL_FAMILY_NAME: string (nullable = true)

所以，当插入到Cassandra我得到下面的错误

tabException in thread "main" java.util.NoSuchElementException: Columns not found in table sample_cbd.model_family_by_id: MODEL_FAMILY_ID, MODEL_FAMILY, CREATE_DATE, LAST_UPDATE_DATE, MODEL_FAMILY_NAME
    at com.datastax.spark.connector.SomeColumns.selectFrom(ColumnSelector.scala:44)