Modifying an existing table to use an ENUM instead of an int

Hi all -

I have an existing table that looks like this:

CREATE TABLE orders
(
  --Bunch of stuff you don't care about
  orderstate integer NOT NULL,
  --Etc
)

with a bunch of data in it.  I've now created this new data type:

CREATE TYPE OrderStateEnum AS ENUM ('Preview', 'InQueue', 'Ordered',
'Error', 'Cancelled');

I want to change the type of "orderstate" from integer to
OrderStateEnum, and cast 0 to Preview, 1 to InQueue, 2 to Ordered,
etc.

I could create a new column, copy all the data over, then delete the
old column, but I suspect there's some cool way to go about doing
this.  Thanks!

Mike

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