reshape VS graphjin

Cool stuff! Do you have any thoughts about how this compares to https://github.com/fabianlindfors/reshape?

From what I know, there is only one project that tries something close to this: the relatively recent Reshape. It uses Postgres views to expose the two versions of the schema and triggers to upgrade/downgrade the new data. It doesn’t do the constraints part as described above, but shows that this approach is possible. Combined with the Xata pull request based workflow, I think the ideal system described above is possible!

My idea is not unique. Reshape is similar, but bigger in scope.

Shameless plug: I’ve been working on a tool called Reshape in this space: https://github.com/fabianlindfors/reshape. It fully automates zero-downtime schema migrations and avoids all the manual work that has been discussed in the comments here.

Anybody interested in this subject might also be interested in a tool for Postgres I’ve been working on, Reshape: https://github.com/fabianlindfors/reshape. It aims to fully automate away all the pain and manual steps zero-downtime migrations normally requires :)

This post is absolutely terrific and has been been my main reference for Reshape, an automated, zero-downtime schema migration tool: https://github.com/fabianlindfors/reshape

I thought the established wisdom is to make schema migration compatible with both the old app and the new app, whenever it is possible? E.g. you can safely add a nullable column, and it shouldn't trip up the old app nor the new app, unless you are using some crappy ORM that does "SELECT *", or you are on an older MySQL version that may take hours/days/weeks to rewrite the whole table just to add a nullable column.

https://github.com/fabianlindfors/reshape, on HN front page a couple weeks ago, has some nice tricks to help with the incompatible cases.

Great article! For anybody interested in this topic, I've been working on a schema migration tool which automates zero-downtime migrations using many of the techniques mentioned: https://github.com/fabianlindfors/reshape. It also uses some other incredible Postgres features, like updatable views and schemas.

It was discussed here on HN about a week back: https://news.ycombinator.com/item?id=29825520

> We have migrated a few fields from varchar to integer. How would your solution deal with this

There is actually an example in the README on how to change a column from TEXT to INTEGER, the technique would be the same the other way around: https://github.com/fabianlindfors/reshape#alter-column

For the cases that require manual handling, that is a bit tricky. I'm not sure Reshape would be able to automate that in any meaningful way so the best thing might just be to fall back to a standard procedure of making the changes in two separate migrations, where the manual changes are done in between.

> Another one is adding foreign keys where the existing data does not conform to the foreign key constraint.

I have given this some thought before as I wanted to add a migration which can add new foreign keys. I think it can be done by writing some migrations first which update the existing data to conform to the constraint, for example adding missing values. This can be done with `alter_column` right now and there will be more comprehensive migrations for data changes in the future.

This one looks interesting if you like GraphQL… https://graphjin.com

You're right. Django made a ton of tables, and it's pretty insightful to think about all the stuff it's trying to consider and a nightmare to migrate that framework. Django might have simplified some stuff, but it's still too opaque for my taste and the overall end goals of the project. Currently, I'm testing using graphjin (it doesn't have the best documentation, but it does boast an SQL generation capability that I philosophically think is the best way to do things).

Checkout GraphJin it's an automatic GraphQL to SQL compiler, you write your database queries in GraphQL instead of SQL and it compiles them into efficient SQL on the fly. Works as a library in GO and NodeJS. https://github.com/dosco/graphjin

In GraphJin an automatic GraphQL to SQL compiler we use the gnomock library it startups a database instance (docker) then create the schema and tests data and finally our code connects to it and runs a series of tests. We run these across Mysql, Postgres and a few other DB's. Gnomock supports a wide range of them. Right now we don't take down the db for every test only between test runs but its fast enough that we could. This whole thing runs of a simple `go test -v .` command and we run it on every commit using a githook. https://github.com/dosco/graphjin/blob/master/tests/dbint_te...

Not exactly GraphQL is just a format to define what data you want back from someplace. You can use it in a browser app to request data from a backend GraphQL server or you can use it as an ORM within your backend app to fetch data from a database using a library like GraphJin. https://github.com/dosco/graphjin

This is more common that you would believe other issues i've seen are no `limit` on the query, fetching all the results and then sorting in your own app code, using wrong joins. Many of these happen while using ORMs as well. SQL is a context switch for more devs and very few understand it and even those that do might not be familiar with the capabilites of your startups db choice.

Shameless plug but this was my motivation behind building GraphJin a GraphQL to SQL compiler and it's my single goto force multipler for most projects. https://github.com/dosco/graphjin

There are tools like Hasura/Haskell, Postgraphile/Node.js or Graphjin/Golang that could generate an automatic graphQL API from a Postgres database. Im new to Elixir and really love it. I wonder if there is anything similar these. I heard about Absinthe for graphQL, however as far as I understand it requires to write your own resolvers. What will it take to create a similar tool in Elixir like the one stated above? How would one go about it?

Its a new thing to me. Will definitely try that out with https://github.com/dosco/graphjin and https://github.com/nautilus/gateway which are golang graphql servers.