如何在 Spark-java 数据框中添加具有常量的列
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How to add column with constant in Spark-java data frame
提问by user2895589
I have imported
我已经进口
import org.apache.spark.sql.Column;
import org.apache.spark.sql.functions;
in my Java-Spark driver
在我的 Java-Spark 驱动程序中
But
但
DataFrame inputDFTwo = hiveContext.sql("select * from sourcing_src_tbl");
inputDFTwo.withColumn("asofdate", lit("2016-10-2"));
here "lit" is still showing error in eclipse(windows).Which library should I include to make it work.
这里的“lit”仍然在 eclipse(windows) 中显示错误。我应该包含哪个库以使其工作。
回答by zero323
Either import object like you do know and use it to access method:
要么像您知道的那样导入对象并使用它来访问方法：
import org.apache.spark.sql.functions;
df.withColumn("foo", functions.lit(1));
or use import staticand call method directly:
或import static直接使用和调用方法：
import static org.apache.spark.sql.functions.lit;
df.withColumn("foo", lit(1));
