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Apache Spark commented on SPARK-37575: -------------------------------------- User 'wayneguow' has created a pull request for this issue: https://github.com/apache/spark/pull/34853 > Empty strings and null values are both saved as quoted empty Strings "" > rather than "" (for empty strings) and nothing(for null values) > --------------------------------------------------------------------------------------------------------------------------------------- > > Key: SPARK-37575 > URL: https://issues.apache.org/jira/browse/SPARK-37575 > Project: Spark > Issue Type: Bug > Components: SQL > Affects Versions: 2.4.0, 3.2.0 > Reporter: Guo Wei > Priority: Major > > As mentioned in sql migration > guide([https://spark.apache.org/docs/latest/sql-migration-guide.html#upgrading-from-spark-sql-23-to-24]), > {noformat} > Since Spark 2.4, empty strings are saved as quoted empty strings "". In > version 2.3 and earlier, empty strings are equal to null values and do not > reflect to any characters in saved CSV files. For example, the row of "a", > null, "", 1 was written as a,,,1. Since Spark 2.4, the same row is saved as > a,,"",1. To restore the previous behavior, set the CSV option emptyValue to > empty (not quoted) string.{noformat} > > But actually, both empty strings and null values are saved as quoted empty > Strings "" rather than "" (for empty strings) and nothing(for null values)。 > code: > {code:java} > val data = List("spark", null, "").toDF("name") > data.coalesce(1).write.csv("spark_csv_test") > {code} > actual result: > {noformat} > line1: spark > line2: "" > line3: ""{noformat} > expected result: > {noformat} > line1: spark > line2: > line3: "" > {noformat} -- This message was sent by Atlassian Jira (v8.20.1#820001) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org