Bug #62137 getObject method can not get Correct rs
Submitted: 10 Aug 2011 10:26 Modified: 10 Aug 2011 19:43
Reporter: zhu suo Email Updates:
Status: Not a Bug Impact on me:
None 
Category:Connector / J Severity:S3 (Non-critical)
Version:5.1.17 OS:Linux (mysql 5.1.57)
Assigned to: CPU Architecture:Any

[10 Aug 2011 10:26] zhu suo 
Description:
	sql="  SELECT CONCAT(4,'6') AS h   ";
	Statement st=con.createStatement();
	ResultSet rs=st.executeQuery(sql);
	while(rs.next()){					System.out.println(rs.getObject(1).getClass().getName());
	}
    

execute the code and  return    "[B"

How to repeat:
execute the code
[10 Aug 2011 19:44] Sveta Smirnova 
Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://dev.mysql.com/doc/ and the instructions on
how to report a bug at http://bugs.mysql.com/how-to-report.php

The driver does not automatically de-serialize objects. You have to use autoDeserialize=true to get behavior you expect.
[12 Aug 2011 21:34] Mark Matthews 
This isn't a bug about de-serialization. It *is* a bug about the types that mysqld returns to clients when mixed types are used. In this case, concat-ing a number and a string together yields a "binary string" in mysql speak, which is required to map to the SQL type VARBINARY, which according to the JDBC specification maps to the java class byte[].

Use a SQL cast() to get a string or number, or whatever you want, but concat-ing a number and a string is really un-defined without that.