-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi again, all --
I apologize in advance for asking kindergarten-level questions on the list, but my head is getting really bruised from this one. I'm trying to understand what makes a relational (not necessarily transactional) database and how, in what forms, MySQL is that. It's my understanding that to truly be relational a column in one table (let's say "sales") must get its value from a column in another table (let's say "customers") rather than just having the same name. That is, it would be easy for anything to have +------------------------+ +------------------------+ | SALES | | CUSTOMERS | +---------+-------+------+ +------+-----------------+ | product | price | cust | | num | name | +---------+-------+------+ +------+-----------------+ | TXLblue | 14.99 | 1136 | | 1136 | richard roe | +---------+-------+------+ +------+-----------------+ | CMMblck | 11.50 | 2408 | | 2408 | jane doe | +---------+-------+------+ +------+-----------------+ | SMMblue | 22.75 | 2408 | | 8421 | bob smith | +---------+-------+------+ +------+-----------------+ where SALES.cust gets filled with the same value as CUSTOMERS.num -- but should the customer number somehow change we're now out of sync, whereas in a truly relational database the fields in the SALES.cust column would *be* the fields in the CUSTOMERS.num column rather than simply having the same value. Am I lost, out of my tree, confused, or bang on? And how (perhaps InnoDB tables) does MySQL support this if I'm not any of the first three? TIA & HAND mysql query, :-D - -- David T-G * There is too much animal courage in (play) [EMAIL PROTECTED] * society and not sufficient moral courage. (work) [EMAIL PROTECTED] -- Mary Baker Eddy, "Science and Health" http://www.justpickone.org/davidtg/ Shpx gur Pbzzhavpngvbaf Qrprapl Npg! -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (FreeBSD) iD8DBQE97SO3Gb7uCXufRwARAooDAKDI6dhugjyejLAEwC5Sjl6Pjqz/nACcDoj0 vUcEuhNZHvTYh+KjGz05/9Q= =hZrX -----END PGP SIGNATURE----- --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
