sequelize.sync({ force: 'if-mismatch' })

[ephys]

Feature Description

Describe the feature you'd like to see implemented

Having the possibility of setting the force option in sequelize.sync to if-mismatch (or if-needed?):

sequelize.sync({ force: 'if-mismatch' }): Promise<boolean>

Describe why you would like this feature to be added to Sequelize

When modifying an existing model during development, none of the existing solutions work very well:

• sequelize.sync() does not update an existing table at all
• sequelize.sync({ alter: true }) will never be able to perfectly update an existing table, so we usually just don't use it at all. (for instance, it's impossible for alter to add a non-null column that doesn't have a default value).
• sequelize.sync({ force: true }) + seeding with dev data works, but it resets the database on every app restart which makes it inconvenient.

So far I've always used sequelize.sync({ force: true }), but I comment it out when I don't need it.

With something like sequelize.sync({ force: 'if-mismatch' }), we could fully reset the database, but only when one of the tables is outdated.

In this design, I'm making that method return true when a synchronization happened. This boolean can then be used by user code to run dev data seeding accordingly.

This would be a non-trivial feature. We'd need to rely on describeTable, which has many quirks. But in time we should be able to implement something like this

Is this feature dialect-specific?

• No. This feature is relevant to Sequelize as a whole.
• Yes. This feature only applies to the following dialect(s):

Would you be willing to resolve this issue by submitting a Pull Request?

• Yes, I have the time and I know how to start.
• Yes, I have the time but I will need guidance.
• No, I don't have the time, but my company or I are supporting Sequelize through donations on OpenCollective.
• No, I don't have the time, and I understand that I will need to wait until someone from the community or maintainers is interested in implementing my feature.

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[fzn0x]

Is it also possible to add new column updated_at into SequelizeMeta for this feature whenever the feature implemented a change to the 'outdated' tables?

[ephys]

What would be the use case for such a column?

[fzn0x]

What would be the use case for such a column?

No specific use case, just did track when the tables is getting updated.

[ephys]

Well SequelizeMeta is managed by sequelize-cli and is about migrations so we'd need a new table for sync. I don't really want to add extra tables unless we have a very good reason to

[fzn0x]

Well SequelizeMeta is managed by sequelize-cli and is about migrations so we'd need a new table for sync. I don't really want to add extra tables unless we have a very good reason to

I see, lets skip that I guess :D