MySQL declares an ENUM inline, right on the column definition. PostgreSQL has no inline enum — you CREATE TYPE a named enum type first, then use it as a column type. pgloader bridges this automatically, with no casting rule required for the default case.

What pgloader’s own docs say

Straight from pgloader’s MySQL reference documentation:

Enum types are declared inline in MySQL and separately with a CREATE TYPE command in PostgreSQL, so each column of Enum Type is converted to a type named after the table and column names defined with the same labels in the same order.

In other words: for a MySQL column like

CREATE TABLE orders (
  id     int PRIMARY KEY,
  status ENUM('pending', 'shipped', 'delivered')
);

pgloader automatically issues the PostgreSQL equivalent, naming the new type after the table and column it came from:

CREATE TYPE orders_status AS ENUM ('pending', 'shipped', 'delivered');

CREATE TABLE orders (
  id     int PRIMARY KEY,
  status orders_status
);

Same labels, same order, no manual CREATE TYPE statement to write by hand, and no casting rule needed in your .load file for the common case — this is pgloader’s default behavior, not something you opt into.

When you’d still write a rule

If you want a specific type name instead of the auto-generated tablename_columnname pattern, or you’re consolidating the same set of labels used across several MySQL columns into one shared PostgreSQL enum type, that’s where a custom CAST rule comes in — the same casting-rules mechanism covered in the Casting Rules & Schema Mapping module of the full course. For the default case, though, there’s nothing to configure.