+ local stmt, err = dosql(sql, host, username);
+ if not stmt then
+ return rollback(nil, err);
+ end
+ local next = stmt:rows();
+ return commit(function()
+ local row = next();
+ return row and row[1];
+ end);
+end
+
+function driver:purge(username)
+ local stmt, err = dosql("DELETE FROM `prosody` WHERE `host`=? AND `user`=?", host, username);
+ if not stmt then return rollback(stmt, err); end
+ local changed, err = stmt:affected();
+ if not changed then return rollback(changed, err); end
+ return commit(true, changed);