Revert "Revert "refactor: added drizzle ORM (#4142)" (#4195)" (#4197)

* Revert "Revert "refactor: added drizzle ORM (#4142)" (#4195)"

This reverts commit bdd320e.

* refactor: use /server/db path

* just test without header

* Revert "just test without header"

This reverts commit 1432c7b.

* fix: fixed bug of upsertUser.

.changeset/empty-cooks-promise.md

@@ -0,0 +1,5 @@
+---
+"geohub": patch
+---
+
+refactor: migrate SQL queries to use drizzle ORM in all endpoints.

CONTRIBUTING.md

@@ -137,6 +137,52 @@ Add the same issue number in the PR description. Example:
 
 You have made your contribution to the GeoHub project.
 
+## Database connection
+
+### download schema from remote database (only first time)
+
+[drizzle ORM](https://orm.drizzle.team/docs/get-started-postgresql#node-postgres) is used to manage data connections in GeoHub.
+
+To pull existing database settings, the following command is used.
+
+```shell
+pnpm drizzle-kit introspect
+```
+
+note. before running introspect, please make sure your `DATABASE_CONNECTION` variable in `.env` is pointing remote database connection.
+
+This will create all migration files under `sites/geohub/drizzle` folder. `schema.ts` should be copied to `src/lib/server/schema.ts` since it is used for sveltekit.
+
+### migrate database schema to remote
+
+If database schema needs to be changed, update `src/lib/server/schema.ts` first.
+
+Then, run the following commands to migrate and push changes to database.
+
+```shell
+pnpm drizzle-kit:generate # generate migration patch files
+pnpm drizzle-kit:migrate # push changes to database
+```
+
+note. before running introspect, please make sure your `DATABASE_CONNECTION` variable in `.env` is pointing the correct database connection.
+
+If you want to migrate database schema to docker, `DATABASE_CONNECTION` can be `postgres://docker:docker@localhost:25432/geodata?sslmode=disable`
+
+### In sveltekit
+
+`$lib/server/db` create drizzle instance for sveltekit. You can import `db` from `$lib/server/db` to connect to the database.
+
+```ts
+import { eq } from "drizzle-orm";
+import { userSettingsInGeohub } from "$lib/server/schema";
+import { db } from "$lib/server/db";
+
+const db = await getClient();
+const settings = await db.query.userSettingsInGeohub.findFirst({
+  where: eq(userSettingsInGeohub.userEmail, user_email),
+});
+```
+
 ## Folder strucuture of GeoHub
 
 This GeoHub repo is using monorepo structure to manage several Javascript packages and Python documentation. The main repository is located at `/sites/geohub` folder, and the source code is under `src`. The structure of `src` folder is as follows.