Gorm Create with non-zero defaults ignores values being inserted

When a struct has gorm default set to a non-zero value, if the value being created is a zero value, it will be ignored and the default will be used.

type Source struct {
  gorm.Model
  Name             string
  URL                string `gorm:"unique;unique_index"`
  Cache             bool  `gorm:"default:true"
}

source := Source{
    Name: "Test",
    URL:    "https://test.com",
    Cache: false,
}

db.Create(&source)

The output:

[5.831ms] [rows:1] INSERT INTO `sources` (`created_at`,`updated_at`,`deleted_at`,`name`,`url`,`cache`) VALUES ("2022-08-04 14:26:16.065","2022-08-04 14:26:16.065",NULL,"Test","https://test.com",true) RETURNING `id`

The expected behavior should be:

[5.831ms] [rows:1] INSERT INTO `sources` (`created_at`,`updated_at`,`deleted_at`,`name`,`url`,`cache`) VALUES ("2022-08-04 14:26:16.065","2022-08-04 14:26:16.065",NULL,"Test","https://test.com",false) RETURNING `id`

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Comment From: github-actions[bot]

Comment From: jlagermann

After some additional testing, I changed the description. When a struct has gorm default set to a non-zero value, if the value being created is a zero value, it will be ignored and the default will be used.

Comment From: github-actions[bot]

Comment From: a631807682

duplicated of https://github.com/go-gorm/gorm/issues/5541

Comment From: jlagermann

This is similar to #5541 but not a duplicate. #5541 only addresses bool values. The issue is related to creating a record with a zero value that has a non-zero default.

Comment From: a631807682

If a value is zero, there is no way to tell whether it is a default value or a user-specified value. You can also use *bool to tell us it is specified value

The reason here also applies to other zero-value types

Comment From: jlagermann

Is there a way to force it to create with the zero value? I can update with zero values with db.Select("*").Updates(&source). Is there a similar method for Create()?

Comment From: a631807682

Not currently supported, are you interested in creating a PR for this?

Comment From: jlagermann

I would be interested if I understood all the pieces that need to be updated to support this. I'm using sqlite3.

Without this capability, the gorm defaults don't really work. The idea with defaults is to provide a value when the input does not provide one. In the current implementation, the default value is used unless the input provides another non-zero value.

If you set the default for a bool to true, it will be created as true 100% of the time. If you set a string default to some value, it can never be created with a zero value.