On Thu, Nov 06, 2003 at 01:02:31PM -0800, Mike Brando wrote: > > > -----Original Message----- > > On Thu, Nov 06, 2003 at 09:59:41AM -0800, Wan, Wenhua wrote: > > > Hi there, > > > > > > Both Oracle and Informix use ROWID to uniquely represent the location of > > > each row of data in a table. ROWID is basically a hidden column or > > > pseudocolumn for each table, and it is the fastest way to retrive a row > > from > > > a table. Does MySql have similar field? If is, what's the name and how > > to > > > access it? > > > > > > Thank you very much in advance for your advice. > > > > http://www.mysql.com/doc/search.php?q=rowid > > > > > Ok, so that search produces this: > > " If the PRIMARY or UNIQUE key consists of only one column and this is of type > integer, you can also refer to it as _rowid (new in Version 3.23.11)."
Yes. > But that's not what a "ROWID" is compared to what I think the > original poster was looking for. One hopes he figured that out after reading the description. > In Oracle for example, a ROWID is the unique address of a row in the > database. Every row, unique key or not has a unique address. Is > there such a thing in MySQL? No. If there was it'd be documented. But at lesat with MyISAM tables, MySQL cannot guarantee the "address" (or row number) of a row. An ALTER/REPAIR/OPTIMIZE may reorder the rows. > ROWIDs are extremely useful for guaranteeing that you are > manipulating the exact row that you think you are. So I've been told. Jeremy -- Jeremy D. Zawodny | Perl, Web, MySQL, Linux Magazine, Yahoo! <[EMAIL PROTECTED]> | http://jeremy.zawodny.com/ MySQL 4.0.15-Yahoo-SMP: up 55 days, processed 2,063,471,142 queries (433/sec. avg) -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
