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From: Robert M. <rob...@gm...> - 2010-01-31 19:24:31
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Christian, After studying this a bit, it seems that DB2 is a bit complex with regard to rsmd.getColumnName and rsmd.getColumnLabel. First, depending on the platform of DB2, a column label can mean different things. For example, in all platforms of DB2 (z/OS, LUW, etc.), in some cases a select statement that uses a column alias, will yield the alias name from getColumnLabel. However, in mainframe DB2 (z/OS, etc.), there is a "LABEL on " statement that is used to give columns a "label" that in some configurations is returned from rsmd.getColumnLabel. There is a new data source property available for DB2 JDBC 4.0 drivers that changes the semantics of these two API methods slightly. http://publib.boulder.ibm.com/infocenter/db2luw/v9r5/index.jsp?topic=/com.ibm.db2.luw.apdv.java.doc/doc/r0052607.html (See useJDBC4ColumnNameAndLabelSemantics property) If the driver conforms to JDBC 4.0, and DB2 server is mainframe, then there are basically two configurations: 1. useJDBC4ColumnNameAndLabelSemantics = DB2BaseDataSource.YES : "LABEL on" column labels are ignored; getColumnLabel = column alias in select statement if provided. If not provided, then it is the column name. 2. useJDBC4ColumnNameAndLabelSemantics = DB2BaseDataSource.NO : "LABEL on" column labels are returned from getColumnLabel. Column aliases are returned from getColumnName. For older drivers the default behavior is item 2 above. Item #1 would potentially solve the issue that Christian is having without a code change to SQuirreL. I would be curious to see if that is correct, if Christian would like to try. According to the configuration instructions in the document I cited, you would need to use a JDBC 4.0 driver and append the following to the JDBC URL: ;useJDBC4ColumnNameAndLabelSemantics=(com.ibm.db2.jcc.DB2BaseDataSource.YES) I'm still planning to convert our usage of getColumnLabel to getColumnName, but I would be curious to see if the above has any effect on the problem with DB2 on the mainframe platform. Rob On Thu, Jan 28, 2010 at 8:26 PM, Robert Manning <rob...@gm...> wrote: > Thanks for confirming that Christian - I suspected that but I wanted > to have another look to be sure. We will take care of this issue > before the 3.1 release in February and when we do there will be a > snapshot that you (and others who might be interested in the impact of > this change) to try out. > > Rob > > On Thu, Jan 28, 2010 at 2:02 PM, Christian Gruenberg > <chr...@di...> wrote: >>>> I also think that if we do this in core, then probably >>>> most if not all of Christian's custom DB2 datatypes are unnecessary. >>>> I skimmed over them so it is possible that I missed something but they >>>> seemed to be merely overriding the core implementation of >>>> getWhereClauseValue() and the like in *DataTypeComponent. I'll take >>>> another look. >> >> You are right, they are unnecessary now if you'll corret the basic datatypes. >> >> Christain >> > |
