* Rhino: > You'll need three alter statements: > - one to add the new column > - one to get rid of the old primary key > - one to set the new column as the primary key
In addition to adding the new column, there will be neccessary to populate the column with unique values. A primary key must allways contain unique values. > Something like this, i.e. I've left out some details of the syntax: > ALTER TABLE FOO ADD USERID CHAR(8); > ALTER TABLE FOO DROP PRIMARY KEY; > ALTER TABLE FOO ADD PRIMARY KEY(USERID); > > Your basic mistake is that you're trying to make all the changes in one > statement; SQL pretty much forces you to change each aspect of the table > in a separate ALTER TABLE statement. This is not correct, you can have multiple changes in the same ALTER TABLE statement, for instance: ALTER TABLE FOO ADD USERID CHAR(8) NOT NULL, DROP PRIMARY KEY, ADD PRIMARY KEY(USERID); This would only work on an empty or a single-row table, or you would get duplicate key errors. -- Roger -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
