peng bo created SPARK-27638:
-------------------------------
Summary: date format yyyy-M-dd comparison isn't handled properly
Key: SPARK-27638
URL: https://issues.apache.org/jira/browse/SPARK-27638
Project: Spark
Issue Type: Bug
Components: SQL
Affects Versions: 2.4.2
Reporter: peng bo
The below example works with both Mysql and Hive, however not with spark.
{code:java}
mysql> select * from date_test where date_col >= '2000-1-1';
+------------+
| date_col |
+------------+
| 2000-01-01 |
+------------+
{code}
The reason is that Spark casts both sides to String type during date and string
comparison for partial date support. Please find more details in
https://issues.apache.org/jira/browse/SPARK-8420.
Based on some tests, the behavior of Date and String comparison in Hive and
Mysql:
Hive: Cast to Date, partial date is not supported
Spark: Cast to Date, "partial date" is supported by defining certain date
string parse rules. Check out {{str_to_datetime}} in
https://github.com/mysql/mysql-server/blob/5.5/sql-common/my_time.c
Here's 2 proposals:
a. Follow Mysql parse rule, but some partial date string comparison cases
wouldn't be supported as well
b. Cast String value to date, if it passes use date.toString, original string
otherwise.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org
