Relational Database Web Cloudbase

---
name: relational-database-web-cloudbase
description: "[Deprecated] Existing CloudBase MySQL Web SDK only. Do not recommend MySQL for new relational apps — use postgresql-development and app.rdb(). Read this only when a browser app must keep using @cloudbase/js-sdk against an environment that already has MySQL."
version: 2.36.2
license: MIT
alwaysApply: false
metadata:
  priority: "5"
  deprecated: "true"
---

## Sibling skills (local only)

Sibling CloudBase skills ship beside this skill. Use local relative paths such as `../auth-tool-cloudbase/SKILL.md`.

If a referenced sibling skill file is missing from this environment, ask the user to install the full CloudBase plugin (or the missing skill). Do **not** HTTP-fetch remote skill or protocol markdown into the agent context.

# CloudBase Relational Database Web SDK

## Activation Contract

### Use this first when

- A browser or Web app must keep using `@cloudbase/js-sdk` against an environment that **already has** CloudBase MySQL.
- Do **not** choose this skill for a new relational app. New relational Web work uses `postgresql-development-cloudbase` and `app.rdb()`.

### Read before writing code if

- You need to distinguish browser SDK usage from MCP database management or backend Node access.
- The request mentions Supabase migration, shared frontend DB client, or browser-side table queries.

### Then also read

- MySQL SQL management and MCP operations -> `../relational-database-mcp-cloudbase/SKILL.md`
- Web auth/login -> `../auth-web-cloudbase/SKILL.md`
- General Web app setup -> `../web-development/SKILL.md`

### Do NOT use for

- MCP-based SQL management, schema changes, or permissions management (provisioning is not offered through MCP).
- Backend/Node service access.
- Document database operations.

### Common mistakes / gotchas

- Initializing SDKs in an MCP management flow.
- Treating `app` itself as the relational database client.
- Re-initializing CloudBase in every component.
- Mixing frontend browser access with admin-style schema mutations.

### Minimal checklist

- Confirm the caller is a Web frontend.
- Keep one shared CloudBase app and one shared relational DB client.
- Route MySQL management/schema work on an existing instance to `relational-database-mcp-cloudbase` (it does not provision). If the task says PostgreSQL, CloudBase PG, PG mode, `app.rdb()`, `queryPgDatabase`, `managePgDatabase`, or RLS, route to `postgresql-development-cloudbase` instead.
- Handle auth separately before data access.

## Overview

This skill standardizes the **browser-side initialization pattern** for CloudBase Relational Database.

After initialization, use `db` with Supabase-style query patterns.

## Installation

```bash
npm install @cloudbase/js-sdk
```

## Canonical initialization

```javascript
import cloudbase from "@cloudbase/js-sdk";

const app = cloudbase.init({
  env: "your-env-id"
});

const auth = app.auth;
// Handle login separately

const db = app.rdb();
```

## Initialization rules

- Initialize synchronously.
- Do not lazy-load the SDK with `import("@cloudbase/js-sdk")` unless the framework absolutely requires it.
- Create one shared `db` client and reuse it.
- Do not invent unsupported `cloudbase.init()` options.

## Quick routing

### Use this skill when

- you are wiring browser components to relational tables
- you are replacing a Supabase browser client with CloudBase
- you need a canonical shared frontend `db` client

### Use `relational-database-mcp-cloudbase` instead when

- you need to create/destroy MySQL
- you need MySQL DDL or write-SQL administration
- you need to inspect or change MySQL table security rules through MCP

### Use `postgresql-development-cloudbase` instead when

- the task says PostgreSQL, CloudBase PG, PG mode, `app.rdb()`, `queryPgDatabase`, `managePgDatabase`, PostgREST, or RLS
- browser-side table code must use PG semantics rather than legacy NoSQL / MySQL management tools

## Example: shared frontend DB client

```javascript
import cloudbase from "@cloudbase/js-sdk";

const app = cloudbase.init({
  env: "your-env-id"
});

export const db = app.rdb();
```

## Example: Supabase-style query

```javascript
const { data, error } = await db
  .from("posts")
  .select("*")
  .order("created_at", { ascending: false });

if (error) {
  console.error("Failed to load posts", error.message);
}
```

## Example: insert / update / delete

```javascript
await db.from("posts").insert({ title: "Hello" });
await db.from("posts").update({ title: "Updated" }).eq("id", 1);
await db.from("posts").delete().eq("id", 1);
```

## Key principle

- `app.rdb()` gives you the relational database client.
- After that point, use Supabase-style query knowledge for table operations.
- Keep schema management and privileged administration outside browser code.