如何将数据帧数据类型转换为String？

Question

I have a hive Table having Date and Timestamp datatypes. I am creating DataFrame using below java code:

SparkConf conf = new SparkConf(true).setMaster("yarn-cluster").setAppName("SAMPLE_APP");
SparkContext sc = new SparkContext(conf);
HiveContext hc = new HiveContext(sc);
DataFrame df = hc.table("testdb.tbl1");

Dataframe schema:

 df.printSchema
root
 |-- c_date: date (nullable = true)
 |-- c_timestamp: timestamp (nullable = true)

I want to covert these columns to String. How can I achieve this?

I need this because of issue : Spark csv data validation failed for date and timestamp data types of Hive

Answer 1

在scala中，我们通常会抛出这样的数据类型：

df.select($"date".cast(StringType).as("new_date"))

Answer 2

您可以执行以下操作：

df.withColumn("c_date", df.col("c_date").cast(StringType))