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Posted to issues@spark.apache.org by "Joby Joje (Jira)" <ji...@apache.org> on 2019/12/06 11:02:00 UTC
[jira] [Created] (SPARK-30149) Schema Definition Spark Read
Joby Joje created SPARK-30149:
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Summary: Schema Definition Spark Read
Key: SPARK-30149
URL: https://issues.apache.org/jira/browse/SPARK-30149
Project: Spark
Issue Type: Bug
Components: PySpark, Spark Core
Affects Versions: 2.4.0
Reporter: Joby Joje
Reading a CSV file with defined schema I am able to load the files and do the processing, which works fine using the below code. The schema is defined as to strictly follow the datatype to record precision's with accuracy.
{code:java}
source_schema = StructType([source_schema = StructType([ StructField("NAME", StringType(), True), StructField("AGE", StringType(), True), StructField("GENDER", StringType(), True), StructField("PROFESSION", StringType(), True), StructField("SALARY", DecimalType(38, 14), True), StructField("BAD_RECORD", StringType(), True)]){code}
{code:java}
df_raw_file = sparksession.read \
.format("csv") \
.option("delimiter", '\t') \
.option("header", "false") \
.option("inferSchema", "true") \
.option("columnNameOfCorruptRecord", "BAD_RECORD") \
.schema(source_schema) \ .load(in_file_list) \
.withColumn("LINE_NUMBER", monotonically_increasing_id()) \
.withColumn("SOURCE_FILE_NAME", input_file_name()){code}
As per the Spark Documentation the mode is {{PERMISSIVE}} by default is its not set and A record with less/more tokens than schema is not a corrupted record to CSV. When it meets a record having fewer tokens than the length of the schema, sets {{null}} to extra fields. When the record has more tokens than the length of the schema, it drops extra tokens.
{code:java}
FILE SCHEMA TEST.CSVFILE SCHEMA TEST.CSV
root
|-- NAME: string (nullable = true)
|-- AGE: string (nullable = true)
|-- GENDER: string (nullable = true)
|-- PROFESSION: string (nullable = true)
|-- SALARY: decimal(38,14) (nullable = true)
|-- BAD_RECORD: string (nullable = true)
|-- LINE_NUMBER: long (nullable = false)
|-- SOURCE_FILE_NAME: string (nullable = false)
OUTPUT THE FILE TEST.CSV
+------+----+------+----------+------------------+---------------------------------+-----------+-----------------+
|NAME |AGE |GENDER|PROFESSION|SALARY |BAD_RECORD |LINE_NUMBER|SOURCE_FILE_NAME |
+------+----+------+----------+------------------+---------------------------------+-----------+-----------------+
|null |null|null |null |null |NAME AGE GENDER PROFESSION SALARY|0 |Test.CSV|
|JOHN |27 |MALE |CEO |300.12314234500000|null |1 |Test.CSV|
|JUSTIN|67 |MALE |CTO |123.23453543450000|null |2 |Test.CSV|
|SARAH |45 |FEMALE|CS |null |null |3 |Test.CSV|
|SEAN |66 |MALE |CA |null |SEAN 66 MALE CA |4 |Test.CSV|
|PHIL |34 |MALE |null |234.98698600000000|null |5 |Test.CSV|
|null |null|null |null |null |JILL 25 BOARD |6 |Test.CSV|
|JACK |30 |MALE |BOARD |null |JACK 30 MALE BOARD |7 |Test.CSV|
+------+----+------+----------+------------------+---------------------------------+-----------+-----------------+{code}
The TEST1.CSV doesnt have the SALARY column so it should have NULLED the column and the BAD_RECORD column should be NULL for the rows, that doesnt seem to have and the values are considered as CORRUPT.
Also when it meets a corrupted record, puts the malformed string into a field configured by {{columnNameOfCorruptRecord}}, and sets other fields to {{null}} this is also not happening and I see this happening only for the JILL row.
{code:java}
FILE SCHEMA TEST1.CSV
root
|-- NAME: string (nullable = true)
|-- AGE: string (nullable = true)
|-- GENDER: string (nullable = true)
|-- PROFESSION: string (nullable = true)
|-- SALARY: decimal(38,14) (nullable = true)
|-- BAD_RECORD: string (nullable = true)
|-- LINE_NUMBER: long (nullable = false)
|-- SOURCE_FILE_NAME: string (nullable = false)
OUTPUT THE FILE TEST1.CSV
+------+----+------+----------+------+--------------------------+-----------+-----------------+ |NAME |AGE |GENDER|PROFESSION|SALARY|BAD_RECORD |LINE_NUMBER|SOURCE_FILE_NAME | +------+----+------+----------+------+--------------------------+-----------+-----------------+
|NAME |AGE |GENDER|PROFESSION|null |NAME AGE GENDER PROFESSION|0 |Test1.CSV|
|JOHN |27 |MALE |CEO |null |JOHN 27 MALE CEO |1 |Test1.CSV|
|JUSTIN|67 |MALE |CTO |null |JUSTIN 67 MALE CTO |2 |Test1.CSV|
|SARAH |45 |FEMALE|CS |null |SARAH 45 FEMALE CS |3 |Test1.CSV|
|SEAN |66 |MALE |CA |null |SEAN 66 MALE CA |4 |Test1.CSV|
|PHIL |34 |MALE |null |null |PHIL 34 MALE |5 |Test1.CSV|
|null |null|null |null |null |JILL 25 BOARD |6 |Test1.CSV|
|JACK |30 |MALE |BOARD |null |JACK 30 MALE BOARD |7 |Test1.CSV|
+------+----+------+----------+------+--------------------------+-----------+-----------------+{code}
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