Skill library / Cursor

SQL Query Helper skill for Cursor

Writing SQL without knowing the schema leads to wrong joins. This skill points Cursor at your schema first, then writes queries that are correct, readable and index-friendly.

What it's good for

• Ad-hoc reporting queries
• Optimising slow queries flagged in logs
• Writing safe migrations

How the skill works

1. Read the schema or migration files to confirm tables and columns
2. Write the query with explicit column lists and aliases
3. Explain each join in one line
4. Suggest indexes if filtering on unindexed columns
5. For writes, wrap in a transaction and show a dry-run SELECT first

Built-in rules

• Never use SELECT * in production queries
• Never run destructive statements without confirmation
• Use parameter placeholders, never string concatenation

Example

You: “Monthly revenue by plan for the last 12 months”
Result: A Postgres query with date_trunc grouping, a join explanation and an index suggestion on invoices(created_at).

SKILL.md template

Save as sql-query-helper/SKILL.md.

---
name: sql-query-helper
description: "Writes and optimises SQL queries against the project's schema, explaining joins and indexes. Use when the user asks for a query, report, migration or to speed up slow SQL."
---

# SQL Query Helper

## Workflow
1. Read the schema or migration files to confirm tables and columns
2. Write the query with explicit column lists and aliases
3. Explain each join in one line
4. Suggest indexes if filtering on unindexed columns
5. For writes, wrap in a transaction and show a dry-run SELECT first

## Rules
- Never use SELECT * in production queries
- Never run destructive statements without confirmation
- Use parameter placeholders, never string concatenation

How to install in Cursor

Put the folder in .cursor/skills/ (or .agents/skills/), or copy the included .mdc file into .cursor/rules/.

Pro tip

Set globs to **/*.sql and your migrations folder so the rule activates with database work.

FAQ

Related skills

• React Component Generator skill for Cursor
• Unit Test Writer skill for Cursor
• Python Refactoring skill for Cursor