On Mon, Sep 02, 2013 at 08:53:18PM +0100, Martin J. Evans wrote: > On 02/09/2013 20:27, Martin J. Evans wrote: > > > >Now, table_info() with no arguments is not mentioned in the DBI pod so > >you could say that is undefined behaviour but it is a little late for > >that now as DBD::ODBC uses it in test code and as far as I know, so do > >others. However, to fix the initial bug I cannot know when empty strings > >are supposed to be undef/NULL and when they are supposed to be empty > >strings. So I can fix the bug as shown but only if I change DBD::ODBC > >test code from table_info() to table_info('%', '%', '%', '%') and I > >cannot change anyone elses code. > > Correction, in that last paragraph (I did warn you), I should have > said table_info() to table_info('%', '%', '%') i.e., > > table_info('%', '', '') returns catalogs only > table_info('', '%', '') returns schemas only > table_info('', '', '', '%') returns types only > table_info('%', '%', '%') returns everything > table_info() did return everything due to workaround in DBD::ODBC > but fixing bug ends up in table_info() returning nothing.
How about changing your test code to table_info('%', '%', '%', '%') and treat table_info() a special case that triggers a warning? Tim.