Hi, That may have the desired effect of two unique keys, but you stil only have one primary key (probably id1,id2). PRI is listed against each column involved in the Primary key.
Regards Quentin -----Original Message----- From: Etienne Marcotte [mailto:[EMAIL PROTECTED]] Sent: Friday, 7 December 2001 9:42 a.m. To: sherzodR Cc: Demirchyan Oganes-AOD098; '[EMAIL PROTECTED]' Subject: Re: Creating MySQL table w/2 primary keys I found a way to have two primary key, if those keys relate on many columns. mysql> create table keytest( -> col1 int not null, -> col2 int not null, -> unique index (id1,id2), -> unique index (id2,id1) Query OK, 0 rows affected (0.01 sec) mysql> describe keytest; +-------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+---------+------+-----+---------+-------+ | id1 | int(11) | | PRI | 0 | | | id2 | int(11) | | PRI | 0 | | +-------+---------+------+-----+---------+-------+ 2 rows in set (0.00 sec) here ya go, two primary key. in my app, it's very useful for the tables linking two other tables (two tables are N:N so the middle one links) +---------+ +-----------+ +----------+ | users | | userdepts | | depts | +---------+ +-----------+ +----------+ | usrID |----<| usrID |>----| deptID | | usrDept | | deptID | | deptName | | usrName | +-----------+ +----------+ +---------+ (do you like my relational DB ascii figure? Then when selecting all linked entried, it uses only the index! Since it's only numbers and the indexes for search in each directions are there.. HTH Etienne sherzodR wrote: > > As far as I know, you can't do tht. What you could do instead is > have one Primary Key col and make another one UNIQUE. > > I did that several times, and it does work! > > -- > > What they need to teach in school is for people to think for themselves. :-) > -- Larry Wall in <[EMAIL PROTECTED]> > > Demirchyan Oganes-AOD098 wrote: > > DO: Hello everyone, > DO: > DO: I have this create table statement, > DO: > DO: drop table IF EXISTS GROUP_CONCLUSION_GROUPING CASCADE; > DO: > DO: CREATE TABLE IF NOT EXISTS GROUP_CONCLUSION_GROUPING( > DO: ANALYSIS_RESULT_ID MEDIUMINT(20) PRIMARY KEY REFERENCES PAD_ANALYSIS_RESULT(ANALYSIS_RESULT_ID), > DO: GROUP_CONCLUSION_ID MEDIUMINT(20) PRIMARY KEY REFERENCES GROUP_CONCLUSION(GROUP_CONCLUSION_ID) > DO: ) Type=InnoDB; > DO: > DO: where I want to create table with 2 primary keys, but it won't let me. > DO: > DO: How could I do it. > DO: > DO: Regards, > DO: > DO: Oganes Demirchyan > DO: Motorola Life Science > DO: 757 S.Raymond > DO: Pasadena, CA 91105 > DO: Tel: 626-584-5900 > DO: email: [EMAIL PROTECTED] > DO: > DO: > DO: --------------------------------------------------------------------- > DO: Before posting, please check: > DO: http://www.mysql.com/manual.php (the manual) > DO: http://lists.mysql.com/ (the list archive) > DO: > DO: To request this thread, e-mail <[EMAIL PROTECTED]> > DO: To unsubscribe, e-mail <[EMAIL PROTECTED]> > DO: Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php > DO: > > --------------------------------------------------------------------- > 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 -- Etienne Marcotte Specifications Management - Quality Control Imperial Tobacco Ltd. - Montreal (Qc) Canada 514.932.6161 x.4001 --------------------------------------------------------------------- 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 The information contained in this email is privileged and confidential and intended for the addressee only. If you are not the intended recipient, you are asked to respect that confidentiality and not disclose, copy or make use of its contents. If received in error you are asked to destroy this email and contact the sender immediately. Your assistance is appreciated. --------------------------------------------------------------------- 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
