the method Comment in schema not migrate db column comment like MySQL

[luckylsx]

Hi, first of all, thanks the ent!

When I migrate the schema, I found the content in Comment defined was not migrate the DB。
the schema define like following:

func (Order) Fields() []ent.Field {
	return []ent.Field{
		field.Int64("id"),
		field.Int64("order_id").
			Positive().
			Default(0).
			Unique().
			Comment("订单号"),
		field.Int64("product_id").Positive().Default(0).Comment("商品id"),
    }
}

But after the table migrate, the DDL like this:

CREATE TABLE `orders` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `order_id` bigint(20) NOT NULL DEFAULT '0',
  `product_id` bigint(20) NOT NULL DEFAULT '0',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;

Expect is:

CREATE TABLE `orders` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `order_id` bigint(20) NOT NULL DEFAULT '0' COMMENT 'order id',
  `product_id` bigint(20) NOT NULL DEFAULT '0' COMMENT 'product id',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;

I want to know How can I migrate with comment or this part is not support?
Thanks!

[a8m]

Hey @luckylsx, the Comment value is added to generated code, but not to the schema migration.

We're working on the new migration framework for ent and plan to add support for this.

[waltcow]

in most case, sql field comment is needed,
maybe ent can provide a config flag in migrateOption like FieldComment

[a8m]

Hey @waltcow! Atlas already supports this, and the change is not that big. I suggest changing this PR to be annotation-based. I'll give them another ping to ensure it's active; if not, one of the Ent's team can take it.

[waltcow]

Hey @waltcow! Atlas already supports this, and the change is not that big. I suggest changing this PR to be annotation-based. I'll give them another ping to ensure it's active; if not, one of the Ent's team can take it.

I'm agree with you, this Comment annotation nested in entsql annotation is more appropriate

[waltcow]

Ent's team can take it now, wait for this fix @a8m

[a8m]

The issue was resolved with: https://entgo.io/docs/schema-annotations#database-comments.

Update your Ent version to master, and check out this tweet to see an example: https://twitter.com/entgo_io/status/1607394587009589248