Re: [Wikitech-l] Database API: Abstracting bitwise operations

On Fri, Jun 12, 2009 at 10:02 AM, Leons Petrazickis<leons.petrazickis(a)gmail.com> wrote: > 1. Refactor the database to not use an integer as a bit field. Just > use four different boolean columns, which works well cross-database. In MySQL, four different boolean columns means four times the storage, as compared to one TINYINT used as a bitfield. So this isn't a good solution. > 2. Add a function to the Database API for each bit operator. > > $sql = $database->bitand('log_deleted', 1); > > 3. Add a function to the Database API to handle all the operators. > > $sql = $database->op('&', 'log_deleted', 1); > or > $sql = $database->op(Database::BITAND, 'log_deleted', 1); These would be the way to do it, I guess. We do something similar for things like conditionals already. I think 2 is preferable to 3, stylistically. On Fri, Jun 12, 2009 at 11:06 AM, Freako F.

> Oracle abstraction solves this problem in makeList function ... the only > weak point for this solution is if you write SQL statements manualy, if > you use Database class functions to create the actual SQL statement this > works and as i was told on #mediawiki manual sql creation should > gradually be rooted out. This isn't a good solution: foreach ($a as $key => $value) { if (strpos($key, ' & ') !== FALSE) $a2[preg_replace('/(.*)\s&\s(.*)/', 'BITAND($1, $2)', $key)] = $value; elseif (strpos($key, ' | ') !== FALSE) $a2[preg_replace('/(.*)\s|\s(.*)/', 'BITOR($1, $2)', $key)] = $value; elseif (!is_array($value)) { if (strpos($value, ' = ') !== FALSE) { if (strpos($value, ' & ') !== FALSE) $a2[$key] = preg_replace('/(.*)\s&\s(.*?)\s=\s(.*)/', 'BITAND($1, $2) = $3', $value); elseif (strpos($value, ' | ') !== FALSE) $a2[$key] = preg_replace('/(.*)\s|\s(.*?)\s=\s(.*)/', 'BITOR($1, $2) = $3', $value); else $a2[$key] = $value; } elseif (strpos($value, ' & ') !== FALSE) $a2[$key] = preg_replace('/(.*)\s&\s(.*)/', 'BITAND($1, $2)', $value); elseif (strpos($value, ' | ') !== FALSE) $a2[$key] = preg_replace('/(.*)\s|\s(.*)/', 'BITOR($1, $2)', $value); else $a2[$key] = $value; } It breaks on all sorts of possible input, like $dbr->select( 'revision', '*', 'rev_deleted&1' ) or $dbr->update( 'user', array( 'user_name' => 'Sam & Max'), $where ), or any number of other things. Not actually tested, but it definitely breaks *somewhere*. _______________________________________________ Wikitech-l mailing list Wikitech-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l