[SPARK-7039] JdbcRdd doesn't support java.sql.Types.NVARCHAR

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.3.1
• Fix Version/s: 1.3.2, 1.4.0
• Component/s: SQL

Environment

Spark 1.3.1

• Assignee: Shuai Zheng
• Reporter: Shuai Zheng
• Created: 21/Apr/15 19:35
• Updated: 22/Apr/15 20:03
• Resolved: 22/Apr/15 20:03

Description

When create a DataFrame from jdbc method through SqlContext:

DataFrame df = sql.jdbc(url, fullTableName);

If there is column type NVARCHAR, below exception will be thrown:

Caused by: java.sql.SQLException: Unsupported type -9
	at org.apache.spark.sql.jdbc.JDBCRDD$.getCatalystType(JDBCRDD.scala:78)
	at org.apache.spark.sql.jdbc.JDBCRDD$.resolveTable(JDBCRDD.scala:112)
	at org.apache.spark.sql.jdbc.JDBCRelation.<init>(JDBCRelation.scala:133)
	at org.apache.spark.sql.SQLContext.jdbc(SQLContext.scala:900)
	at org.apache.spark.sql.SQLContext.jdbc(SQLContext.scala:852)

When comparing the code between JDBCRDD.scala and java.sql.Types.java, the only type is not supported in JDBCRDD.scala is NVARCHAR. Because NCHAR is supported, so I think this is just a small mistake that people skip this type instead of ignore it intentionally.

Issue Links

• links to: [Github] Pull Request #5618 (szheng79)