This will work.... thanks... That's what I want a unique key based on two columns.
-----Original Message----- From: Jonathan Hilgeman [mailto:[EMAIL PROTECTED]] Sent: Monday, November 12, 2001 12:09 PM To: 'Brendin'; [EMAIL PROTECTED] Subject: RE: primary key based on unique value for two columns You can't use a primary key for that, but you CAN make a unique two-column key: ALTER TABLE MyTable ADD UNIQUE MyNewIndex (Column1,Column2) - Jonathan -----Original Message----- From: Brendin [mailto:[EMAIL PROTECTED]] Sent: Monday, November 12, 2001 10:37 AM To: [EMAIL PROTECTED] Subject: primary key based on unique value for two columns I would like to have a table that has a primary key defined on a combination of two columns in the table. In other words a unique key based upon the values in two columns. I don't think I am able to do this in mysql. I think you can only have a primary key on one column and not on a combination of columns. If I am wrong please correct me. I am looking for work arounds. I have thought of one. That would be to concatenate the columns and use a field terminator such as a - to separate the values or (columns) in the single column. Then you could use string functions to parse the columns. Ex: For column 1 in concatenated column left( ColumnName, (instr( ColumnName, '-') - 1) ) For column 2 in concatenated column Substr (ColumName, (instr ( ColumnName, '-') + 1) , length(ColumnName)- (instr ( ColumnName, '-') + 1) ) Is there any other way to do this? --------------------------------------------------------------------- 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 --------------------------------------------------------------------- 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
