schema-design

schema-design is a cursor rule for Cursor from girijashankarj/cursor-handbook. It costs 0 tokens per session (566 once invoked), scanned A, original, MIT.

A set of rules for designing database tables, columns, keys, indexes, constraints, timestamps, and soft deletion, where records are marked inactive instead of removed.

In plain words
What is it for?
Use it when creating tables or reviewing database schemas, naming conventions, relationships, constraints, and record-lifecycle fields.
Why use it?
It keeps database structures consistent and helps preserve records while making relationships and data rules clear.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/girijashankarj/cursor-handbook/schema-design
Clone the repo
git clone --depth 1 https://github.com/girijashankarj/cursor-handbook

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for schema-design

README.md
[![agentmods](https://agentmods.dev/badge/rules/girijashankarj/cursor-handbook/schema-design.svg)](https://agentmods.dev/rules/girijashankarj/cursor-handbook/schema-design)
Your own site
<a href="https://agentmods.dev/rules/girijashankarj/cursor-handbook/schema-design"><img src="https://agentmods.dev/badge/rules/girijashankarj/cursor-handbook/schema-design.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 566 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00000 $0.00566
Opus 5 $0.00000 $0.00283
Sonnet 5 $0.00000 $0.00113
Haiku 4.5 $0.00000 $0.00057

Measured 2d ago against content hash a2f138df74d6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

schema-design scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/database/schema-design.mdc · 61 lines

How it starts

The opening of the file, as written. The whole thing — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Database Schema Design

Naming Conventions ({{CONFIG.database.naming}})

Object Convention Example
Tables Plural snake_case orders, order_items
Columns snake_case created_at, order_total
Primary keys id id
Foreign keys {table_singular}_id order_id, user_id
Indexes idx_{table}_{columns} idx_orders_user_id
Unique constraints uq_{table}_{columns} uq_users_email
Check constraints chk_{table}_{description} chk_orders_positive_total

Standard Table Template

CREATE TABLE {table_name} (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    -- Business columns here
    {{CONFIG.database.softDeleteField}} BOOLEAN NOT NULL DEFAULT true,
    {{CONFIG.database.timestampFields.created}} TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW(),
    {{CONFIG.database.timestampFields.updated}} TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW(),
    created_by UUID REFERENCES users(id),
    updated_by UUID REFERENCES users(id)
);

-- Auto-update timestamp trigger
CREATE TRIGGER set_updated_at
    BEFORE UPDATE ON {table_name}
    FOR EACH ROW
    EXECUTE FUNCTION update_{{CONFIG.database.timestampFields.updated}}();

-- Default index on soft delete flag
CREATE INDEX idx_{table_name}_active
    ON {table_name}({{CONFIG.database.softDeleteField}})
    WHERE {{CONFIG.database.softDeleteField}} = true;

Data Types

Use Case Type Notes
Identifiers UUID Use gen_random_uuid()
Money/currency NUMERIC(19,4) Never use FLOAT
Timestamps TIMESTAMP WITH TIME ZONE Always timezone-aware
Short text VARCHAR(n) With appropriate length
Long text TEXT For unbounded text
Booleans BOOLEAN Not integers
Enums VARCHAR or native ENUM Prefer VARCHAR for flexibility
JSON data JSONB Not JSON (JSONB is indexed)

Relationship Patterns

  • Use foreign keys with appropriate ON DELETE/UPDATE actions
  • Junction tables for many-to-many relationships
  • Consider denormalization for read-heavy queries
  • Use database-level constraints for data integrity

Read the full file on GitHub · 61 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 61 lines · 0 tokens per session scan A a2f138df74d6

Subscribe to this mod's changes

schema-design is a cursor rule published in the GitHub repository girijashankarj/cursor-handbook (30 stars, last pushed 6d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 566 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.