spark sql dataframe 写 hdfs 文本 报错：text datasource support only a single colum, and you have 2 columns

现象：

spark sql  程序中

resultFrame.coalesce(1).write.text(outputPath)

报错 text datasource support only a single colum, and you have 2 columns

解决：

将结果连接为一列，使用 

concat_ws

如 

select concat_ws('_', name, age) from students;