Better documentation for HCL schema column default values

[sm3142]

First off, thanks for the great tool. I know that DB migrations and how to handle them are an extremely divisive topic, but Atlas serves my needs perfectly (and without dragging JRE😬 along with it).

I have a small suggestion though for improving the documentation on column default values in HCL schema definitions, specifically when they're not a literal value, but come from a builtin or extensions function. Was floundering on this for quite a while until I finally realized I could do a reverse-lookup by creating a table with the desired column definition and then inspect the schema with atlas itself to get to the HCL equivalent. In the end, something like:

CREATE TABLE t (
  id INT
  ts TIMESTAMPTZ DEFAULT NOW()
);

is reported in HCL as:

table "t" {
  schema = schema.public
  column "id" {
    null = true
    type = integer
  }
  column "ts" {
    null    = true
    type    = timestamptz
    default = sql("now()")
  }
}

Hah!

But I guess this could be made a bit easier to find out for others? 😉