Is there an equivalent to *gorm.DB.NewRecord() that was in GORM 1?

[Robbie-Perry]

Your Questio n

In GORM 1, there was a function to check if a record was new, by seeing if its primary key was set. This does not exist anymore in GORM 2.

The document you expected this should be explained

It doesn't seem to be in the changelog of breaking changes.

Expected answer

Is there an equivalent function, or a new way of achieving this (without knowing about the actual model being checked)?

[github-actions]

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[jinzhu]

Hello,

Could you let me know your use case that need to know it is a new record or not?

There were many people thought GORM will check database to check if the record is new or not, to avoid the misunderstanding, we removed the method.

We haven't list some changes like this one that could be caught by the compiler in the release note, but let me know your use case first.

Thank you.

[Robbie-Perry]

@jinzhu I have a use case where some code handles arbitrary data types, where the primary key is unknown. I used NewRecord() to see if the primary keys were set on the item before performing an update (since doing an update on an item with empty keys would instead create a new one).

[github-actions]

This issue has been automatically marked as stale as it missing playground pull request link, checkout https://github.com/go-gorm/playground for details, it will be closed in 2 days if no further activity occurs. if you are asking question, please use the Question template, most likely your question already answered https://github.com/go-gorm/gorm/issues or described in the document https://gorm.io ✨ Search Before Asking ✨

[jinzhu]

@jinzhu I have a use case where some code handles arbitrary data types, where the primary key is unknown. I used NewRecord() to see if the primary keys were set on the item before performing an update (since doing an update on an item with empty keys would instead create a new one).

So if no primary key exist, no operation will perform?

[Robbie-Perry]

So if no primary key exist, no operation will perform?

Or more so, the behaviour differs depending on whether or not there is a primary key present.

[github-actions]

This issue has been automatically marked as stale as it missing playground pull request link, checkout https://github.com/go-gorm/playground for details, it will be closed in 2 days if no further activity occurs. if you are asking question, please use the Question template, most likely your question already answered https://github.com/go-gorm/gorm/issues or described in the document https://gorm.io ✨ Search Before Asking ✨

[jinzhu]

So if no primary key exist, no operation will perform?

Or more so, the behaviour differs depending on whether or not there is a primary key present.

usually the upsert / insert ignore could handle most cases, if this is required, maybe write a wrapper based on the API listed here https://gorm.io/docs/write_plugins.html

I didn't saw a strong requirement currently, so compare to the confusion it caused and the benefit, I prefer to not have it right now

[atz]

Here's some dev's workaround combining .Attrs() and a non-gorm struct field:
https://www.youtube.com/watch?v=JhsgV1RsIpQ

It's not super robust, mainly solves a use case in testing.