Tim Bunce wrote: > On Tue, Jul 20, 2010 at 09:46:42PM +0100, Martin J. Evans wrote: >> [...] >> >> As a result of the above, I don't see any way of supporting the existing >> blob_read in DBI and as it is undocumented anyway and no DBDs seem to >> use it > > Feel free to mark it deprecated in the DBI docs..
It turns out I was mistaken as DBD::Oracle does implement blob read although I've not tested it works. Someone, in the distant past attempted an implementation in DBD::ODBC but it does not work and is seriously flawed. I guess since DBD::Oracle does implement it I should document it? I have implemented my own odbc_lob_read and if I can find time I might try and wrap a blob_read around it. >> I've put a test implementation together as: >> >> odbc_lob_read(sth, colno, buf, length, \%attrs) >> >> where \%attrs can contain TYPE => SQL_type. > >> I appreciate this RFC is quite long and I'm guessing few people will get >> to the end. Increasingly, I'm working with several DBDs and the >> differences between them (beyond SQL differences) is proving VERY >> frustrating. It would be nice to try and sort out lob reading and whilst >> I'm on a roll, SQLMoreResults/more_results, last_insert_id, lob_write, >> binding with a specific type etc but I guess since some of these have >> been covered before and we didn't get too far in the past that perhaps >> there is not a lot of interest in it. I'd like to fit DBD::ODBC with >> DBI's blob_read but I don't think it works for DBD::ODBC as it stands >> and I note other DBDs have provided their own lob reading methods >> substantially different so I'm guessing they found that too. > > I encourage driver authors to implement a 'natural' private API first > before working together to agree on a common API for the DBI. > (The blob_read API is an example of what happens when the DBI specifies > things before drivers support them.) Yes although I slightly misinformed you - sorry. I'll try and revisit this in the next few weeks. >> With Perl 6 perhaps on the horizon and Tim's current interest in JDBC I >> think we are well advised to sort some of this out in Perl 5 first. It >> makes little difference to me right now as I'll implement what I need >> now and move on but I'm prepared to work to a DBI interface for the >> common goal. Some of this is not going to go away - you only have to >> watch perl monks to see the frustration with last_insert_id, lob >> reading, binding columns with types etc across DBDs to know this is >> proving troublesome for the average user. > > Tim. Martin -- Martin J. Evans Easysoft Limited http://www.easysoft.com
