relational-database-mcp-cloudbase

When to use this skill

• Inspecting or querying data in tables
• Modifying data or schema (INSERT/UPDATE/DELETE/DDL)
• Reading or changing table security rules

• Building Web or Node.js applications that talk to CloudBase Relational Database (use the Web/Node Relational Database skills)
• Auth flows or user identity (use the Auth skills)

How to use this skill (for a coding agent)

1. Recognize MCP context
   • If you can call tools like

     executeReadOnlySQL

     ,

     executeWriteSQL

     ,

     readSecurityRule

     ,

     writeSecurityRule

     , you are in MCP context.
   • In this context, never initialize SDKs for CloudBase Relational Database; use MCP tools instead.
2. Pick the right tool for the job
   • Reads →

     executeReadOnlySQL

   • Writes/DDL →

     executeWriteSQL

   • Inspect rules →

     readSecurityRule

   • Change rules →

     writeSecurityRule

3. Always be explicit about safety
   • Before destructive operations (DELETE, DROP, etc.), summarize what you are about to run and why.
   • Prefer running read-only SELECTs first to verify assumptions.

Available MCP tools (CloudBase Relational Database)

1.

executeReadOnlySQL

• Purpose: Run

  SELECT

  queries (read-only).
• Use for:
  • Listing rows, aggregations, joins.
  • Inspecting data before changing it.

SELECT id, email FROM users WHERE active = true ORDER BY created_at DESC LIMIT 50;

2.

executeWriteSQL

• Purpose: Run write or DDL statements:

  • INSERT

    ,

    UPDATE

    ,

    DELETE

  • CREATE TABLE

    ,

    ALTER TABLE

    ,

    DROP TABLE

• Use for:
  • Data migrations
  • Fixing or seeding data
  • Schema changes

_openid

_openid VARCHAR(64) DEFAULT '' NOT NULL

💡 Note about

_openid

: When a user is logged in, the

_openid

field is automatically populated by the server with the current user's identity. You do NOT need to manually set this field in INSERT operations - the server will fill it automatically based on the authenticated user's session.

• The target tables and conditions are correct.
• You have run a corresponding

  SELECT

  via

  executeReadOnlySQL

  when appropriate.

3.

readSecurityRule

• Purpose: Read security rules for a given table.
• Use for:
  • Understanding who can read/write a table.
  • Auditing permissions on sensitive tables.

• READONLY

  – anyone can read, no one can write

• PRIVATE

  – only authenticated users can read/write

• ADMINWRITE

  – anyone can read, only admins can write

• ADMINONLY

  – only admins can read/write

• CUSTOM

  – custom security logic

4.

writeSecurityRule

• Purpose: Set or update security rules for a table.
• Use for:
  • Hardening access to sensitive data
  • Opening up read access while restricting writes
  • Applying custom rules when needed

• Clearly explain the intent (who should read/write what).
• Prefer standard rule types (

  READONLY

  ,

  PRIVATE

  , etc.) before

  CUSTOM

  .

Scenario 1: Safely inspect data in a table

1. Use

   executeReadOnlySQL

   with a limited

   SELECT

   :
   • Include a

     LIMIT

     clause.
   • Filter by relevant conditions.
2. Review the result set and confirm it matches expectations.

Scenario 2: Apply a schema change

1. Use

   executeReadOnlySQL

   to inspect the current schema or data (if needed).
2. Plan the

   CREATE TABLE

   /

   ALTER TABLE

   statement.
3. Run it once via

   executeWriteSQL

   .
4. Optionally, validate by running

   SELECT

   again.

• What schema change you are making.
• Why it is safe in the current context.

Scenario 3: Tighten security rules on a sensitive table

1. Call

   readSecurityRule

   for the table to see current settings.
2. Decide on the target rule (e.g., from

   READONLY

   →

   PRIVATE

   ).
3. Explain the change and why it matches the user’s requirements.
4. Call

   writeSecurityRule

   with the new rule.
5. Optionally, re-read the rule to confirm the update.

Key principle: MCP tools vs SDKs

• MCP tools are for agent operations and database management:
  • Run ad-hoc SQL.
  • Inspect and change security rules.
  • Do not depend on application auth state.
• SDKs are for application code:
  • Frontend Web apps → Web Relational Database skill.
  • Backend Node apps → Node Relational Database quickstart.