AutoIncrement fields on databases without autoincrement field

Question

In MS Sql Server is easy create autoincrement fields. In my systems I stopped to use autoincrement fields for primary keys, and now I use Guid\'s. It was awesome, I\'ve got

Answer 1

The traditional solution is to have a table of ids that look something like this

CREATE TABLE ids (
  tablename VARCHAR(32) NOT NULL PRIMARY KEY,
  nextid INTEGER
)

which s populated with one row per table when you create the database.

You then do a select to get the next next id for the table you are inserting into, increment it and then update the table with the new id. Obviously, there are locking issues here, but for databases with moderate insert rates it works well. And it is completely portable.