Docs are misleading for `casing`

[nimonian]

When the casing parameter is described in the docs, we see this example:

// schema.ts
import { drizzle } from "drizzle-orm/node-postgres";
import { integer, pgTable, varchar } from "drizzle-orm/pg-core";
export const users = pgTable('users', {
  id: integer(),
  firstName: varchar()
})

// db.ts
const db = drizzle({ connection: process.env.DATABASE_URL, casing: 'snake_case' })

// query.ts
await db.select().from(users);

However, this clearly won't work. The casing param is provided at runtime, and drizzle is not aware of any column aliasing settings during migration. As a minimum working example, this fails. The column is named firstName in the database.

---

Now, through some amount of experimentation, I discovered that I can provide a casing option to defineConfig like this:

export default defineConfig({
  // ...
  casing: 'snake_case'
});

But, as far as I can tell, this is undocumented.

---

Proposal: if I'm correct in the above, I propose to properly document the casing option to defineConfig, and also make it clear that this option must be specified when discussing the casing in the schema declaration docs.

I am happy to make a PR, but I need someone more knowledgeable in Drizzle to confirm that what I've said is accurate.

[MikeMcDonald83]

Same here. I don't mean to be repetitive. I'm just trying to clarify the issue.

I defined my models with camelCase. If I use casing: 'snake_case' in the drizzle instancing line but not in the config file, or vice versa, queries using camelCase keys will throw errors.

This isn't necessarily bad. I get the separation of concerns. Maybe your schema is defined with snake_case and you only need conversion at runtime. Maybe another team is working on a different client for the same database.

I'm not a drizzle expert, but I think it's pretty clear how this behavior works and why the docs are confusing. config.casing should be documented and referenced in the section you've included.

If you do a PR, I have another nitpick. That section uses the terms "model names" and "table names" to talk about column name conversion. After testing, I couldn't achieve any automatic table name conversion. casing seems to only apply to column names. Maybe I'm missing something though.