sure you can CREATE TABLE xx (field1 INT NOT NULL,field2 INT NOT NULL,PRIMARY KEY (field1,field2))
and you have table xx with unique key in two fields hand primoz ----- Original Message ----- From: "Brendin" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, November 12, 2001 7:37 PM 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
