1. The column types must match in order to establish a foreign key relationship. Alter the data type would invalidate the Foreign key. Therefore the key must be dropped first.
2. You can not have a relationship on a column that does not exists. Once again the key must first be dropped. 3-4. Currently the user is unable to name Foreign key constraints. Consequently the only way to know the constraint names is to use `show create table`. On Thu, 18 Mar 2004, Gilad Buzi wrote: > > Hello, > Does anyone have any idea why the following don't work in MySQL > 4.1.1-alpha with InnoDB tables: > 1. cannot change column type without first dropping the foreign key > (when there is one) > 2. cannot drop the column without first dropping the foreign key (if > there is one) > 3. cannot explicitly define a constraint's name when creating it. > 4. cannot automatically figure out the names of the constraints > associated with a column without manually parsing the results of "show > create table" > > I sent a more detailed explanation a couple of days ago. I'm just > wondering if this is by design or something planned to be fixed. > > thanks, > > *Gilad Ezra Buzi > *R&D Engineer > Open Source Advocate > > *Concatel* > Avenida Puertos de Europa 100, > 08040 Barcelona (Spain) > tel. +34.93.567.97.10 > fax +34.93.567.97.11 > > http://www.concatel.com > > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
