Bug #44862 getBestRowIdentifier does not return resultset as per JDBC API specifications

• Submitted: 14 May 2009 8:38
• Modified: 26 May 2009 10:49
• Reporter: Vivekanand Bachche
• Status: Closed
• Category: Connector / J
• Severity: S3 (Non-critical)
• Version: 5.1.7
• OS: Windows
• CPU Architecture: Any

[14 May 2009 8:38] Vivekanand Bachche

Description:
Result set returned by getBestRowIdentifier (Database metadata) does not have format as defined in the specifications. Third column i.e. "DATA_TYPE", of the result set is expected to be of type ‘integer’ where MySQL driver returns it as ‘smallint’.

This can give critical problems with BI tools which perform strict checking before retreiving metadata information.

How to repeat:
public void testMetadata() {

               Class.forName("com.mysql.jdbc.Driver");
               Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb?user=myself&password=mypassword");
               DatabaseMetaData metadata = connection.getMetaData();
               ResultSet bestRowIdentifiers = metadata.getBestRowIdentifier("mysql", null, "db", DatabaseMetaData.bestRowNotPseudo, true);

               ResultSetMetaData rsmd = bestRowIdentifiers.getMetaData();             
               System.out.println("Column Name is : " + rsmd.getColumnName(3));	// It is “DATA_TYPE”
               System.out.println("Column Type is : " + rsmd.getColumnType(3));	// Expected type here is Integer i.e. 4
}

[14 May 2009 10:40] Vivekanand Bachche

Logical cause and fix looks to be simialar for following bugs-
44791
44862
44863
44865
44867
44868
44869

[14 May 2009 11:09] Vivekanand Bachche

Please exclude 44791 from the list in my previous comment.

[14 May 2009 16:53] Valeriy Kravchuk

Thank you for the problem report.

[22 May 2009 20:55] Mark Matthews

Fixed, see http://bazaar.launchpad.net/~mark-mysql/connectorj/5.1/revision/793

[26 May 2009 10:49] Tony Bedford

An entry was added to the 5.1.8 changelog:

The result set returned by getBestRowIdentifier() did not have the format defined in the JDBC API specifications. The third column, DATA_TYPE, of the result set should be of type INTEGER. Connector/J however returns SMALLINT.