chore: update doc to make DATABASE_URL required

.env.example

@@ -1,2 +1,3 @@
 # see process.d.ts 
+DATABASE_URL=postgresql://postgres:YOUR_PASSWORD@localhost:5432/sqlchat?schema=sqlchat
 OPENAI_API_KEY=YOUR_OPENAI_API_KEY

README.md

@@ -61,45 +61,46 @@ docker run --name sqlchat --platform linux/amd64 --env OPENAI_API_KEY=xxx --env
 
 ## Local Development
 
-1. Make a copy of the example environment variables file;
+1. Make a copy of the example environment variables file:
 
-   ```bash
+    ```bash
-   cp .env.example .env
+    cp .env.example .env
-   ```
+    ```
 
-2. Add your [API key](https://platform.openai.com/account/api-keys) and OpenAI API Endpoint(optional) to the newly created `.env` file;
+1. Add your [API key](https://platform.openai.com/account/api-keys) and OpenAI API Endpoint(optional) to the newly created `.env` file.
 
-3. Install dependencies and start the dev server;
+1. Start a Postgres instance. For mac, you can use [StackbBricks](https://stackbricks.app/), [DBngin](https://dbngin.com/) or [Postgres.app](https://postgresapp.com/). Create a database:
 
-   ```bash
+    ```sql
-   pnpm i && pnpm dev
+    CREATE DATABASE sqlchat;
-   ```
+    ```
-
+    In `.env` file, assign the connection string to `DATABASE_URL`.
-### Database Setup
 
 1. Install dependencies
 
-   ```bash
+    ```bash
-   pnpm i
+    pnpm i
-   ```
+    ```
 
-1. Generate prisma client from the model
+1. Generate schema
 
-   ```bash
+    1. Generate prisma client from the model
-   pnpm prisma generate
-   ```
 
-1. Migrate schema
+        ```bash
+        pnpm prisma generate
+        ```
 
-   ```bash
+    1. Migrate schema
-   pnpm prisma migrate dev
-   ```
 
-1. Seed data
+        ```bash
+        pnpm prisma migrate dev
+        ```
 
-   ```bash
+    1. (Optional) Seed data
-   pnpm prisma db seed
+
-   ```
+        ```bash
+        pnpm prisma db seed
+        ```
 
 ## Star History
 

process.d.ts

@@ -2,12 +2,13 @@ declare namespace NodeJS {
   export interface ProcessEnv {
     // Required. Node environment.
     NODE_ENV: string;
+    // Required. Postgres database connection string to store the data.
+    // e.g. postgresql://postgres:YOUR_PASSWORD@localhost:5432/sqlchat?schema=sqlchat
+    DATABASE_URL: string;
     // Required. Do not share your OpenAI API key with anyone! It should remain a secret.
     OPENAI_API_KEY: string;
     // Optional. OpenAI API endpoint. Defaults to https://api.openai.com.
     OPENAI_API_ENDPOINT: string;
-    // Optional. Database connection string to store the data.
-    DATABASE_URL: string;
     // Optional. API key to protect the backend API endpoint.
     // This needs to be exposed to the frontend and must be prefixed with NEXT_PUBLIC_.
     NEXT_PUBLIC_API_KEY: string;