[jira] [Commented] (SPARK-24943) Convert a SQL Struct to StructType

["Varun Bharill (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/SPARK-24943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17413358#comment-17413358 ] 

Varun Bharill commented on SPARK-24943:
---------------------------------------

Hi [~hyukjin.kwon], 
I am on pyspark-3.1.2. I am looking for this functionality to parse a ddl string to StructType object in python.

1. Can you please clarify if there is an equivalent version of DataType.fromDDL function in pyspark? Currently, I see that there is a private method - pyspark.sql.types._parse_datatype_string.
2. The above method lacks support for parsing uniontype, char, and varchar. Could you please confirm if they are still unsupported for the ddl to struct object conversion?


{code:java}
pyspark.sql.types._parse_datatype_string("temp CHAR(10)") {code}
gives below error

Traceback (most recent call last):
{code:java}
File "/Users/vbharill/PycharmProjects/scripts/outlawenv/lib/python3.8/site-packages/pyspark/sql/types.py", line 841, in _parse_datatype_string
 raise e
 File "/Users/vbharill/PycharmProjects/scripts/outlawenv/lib/python3.8/site-packages/pyspark/sql/types.py", line 831, in _parse_datatype_string
 return from_ddl_schema(s)
 File "/Users/vbharill/PycharmProjects/scripts/outlawenv/lib/python3.8/site-packages/pyspark/sql/types.py", line 822, in from_ddl_schema
 return _parse_datatype_json_string(
 File "/Users/vbharill/PycharmProjects/scripts/outlawenv/lib/python3.8/site-packages/pyspark/sql/types.py", line 893, in _parse_datatype_json_string
 return _parse_datatype_json_value(json.loads(json_string))
 File "/Users/vbharill/PycharmProjects/scripts/outlawenv/lib/python3.8/site-packages/pyspark/sql/types.py", line 910, in _parse_datatype_json_value
 return _all_complex_types[tpe].fromJson(json_value)
 File "/Users/vbharill/PycharmProjects/scripts/outlawenv/lib/python3.8/site-packages/pyspark/sql/types.py", line 596, in fromJson
 return StructType([StructField.fromJson(f) for f in json["fields"]])
 File "/Users/vbharill/PycharmProjects/scripts/outlawenv/lib/python3.8/site-packages/pyspark/sql/types.py", line 596, in <listcomp>
 return StructType([StructField.fromJson(f) for f in json["fields"]])
 File "/Users/vbharill/PycharmProjects/scripts/outlawenv/lib/python3.8/site-packages/pyspark/sql/types.py", line 441, in fromJson
 _parse_datatype_json_value(json["type"]),
 File "/Users/vbharill/PycharmProjects/scripts/outlawenv/lib/python3.8/site-packages/pyspark/sql/types.py", line 906, in _parse_datatype_json_value
 raise ValueError("Could not parse datatype: %s" % json_value)
ValueError: Could not parse datatype: char(10){code}

Can you please clarify?

> Convert a SQL Struct to StructType
> ----------------------------------
>
>                 Key: SPARK-24943
>                 URL: https://issues.apache.org/jira/browse/SPARK-24943
>             Project: Spark
>          Issue Type: Improvement
>          Components: SQL
>    Affects Versions: 2.3.1
>            Reporter: mahmoud mehdi
>            Priority: Minor
>             Fix For: 2.4.0
>
>
> The main goal of this User Story is to add a method to StructType which does the opposite to what does the sql method.
> For example, for the following SQL Struct : 
> {code:java}
> df.schema.sql
> //STRUCT<`price`: STRUCT<`amount`: BIGINT, `currency`: STRING>>{code}
>  We'll have the following output : 
> {code:java}
> StructType.fromSql(df.schema.sql)
> //StructType(StructField(price,StructType(StructField(amount,LongType,true), //StructField(currency,StringType,true)),true))
> {code}
>  



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org