https://github.com/timbo-rafa/type-safe-prisma-query
https://github.com/timbo-rafa/type-safe-prisma-query
postgresql prisma-orm problem typescript workaround
Last synced: 3 months ago
JSON representation
- Host: GitHub
- URL: https://github.com/timbo-rafa/type-safe-prisma-query
- Owner: timbo-rafa
- Created: 2024-11-18T21:09:23.000Z (7 months ago)
- Default Branch: main
- Last Pushed: 2024-11-19T00:25:42.000Z (7 months ago)
- Last Synced: 2025-01-26T19:43:23.435Z (5 months ago)
- Topics: postgresql, prisma-orm, problem, typescript, workaround
- Language: TypeScript
- Homepage:
- Size: 338 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# Problem Statement
ORMs often struggle to enforce type-safety to queries with partial data and joins.
This repository contains a small code sample on how to achieve that with Prisma ORM.
On our [repository example](/src/posts/broken-post.repository.ts),
we try to select only the email field from the user table, along only with their posts' title. Prisma currently does not allow us to do that and errors out:
Similarly, if we try Prisma validators as suggested on the post [Operating against partial structures](https://www.prisma.io/docs/orm/prisma-client/type-safety/operating-against-partial-structures-of-model-types), prisma seems to join with the User table twice, one correctly hiding the "name" field, but the second joins the complete table incorrectly:
# Solution
In order to solve these problematic joins, we can generate one type per table and merge them in Typescript, as shown in [post.entities.ts](/src/posts/post.entities.ts).
Since we will do that multiple times across different features, we can extract this type logic into a generic for reusability as is in [posts-using-generics.entities.ts](/src/posts/post-using-generics.entities.ts)
It's correctness can be seen by type errors as below:
We can then use this type on query results returned by prisma.
However, since the typed query does not allow `select` and `include`, we may need to resort to [prisma.$queryRaw](https://www.prisma.io/docs/orm/prisma-client/using-raw-sql/raw-queries#queryraw),
in which case the raw sql will **not** be type-safe. You may want to consider tools like [SafeQL](https://safeql.dev/compatibility/prisma.html),
or migrating to Prisma 5.19.0+, so you can use Prisma's [TypedSQL](https://www.prisma.io/docs/orm/prisma-client/using-raw-sql/typedsql)
(in preview at time of writing)
# Try it yourself
After cloning repository:
```bash
npm install
prisma generate
```
Then go to [posts-using-generics.entities.ts](/src/posts/post-using-generics.entities.ts) to see the type errors in your editor