name: sql
description: Guide for working with SQL queries, in particular for SQLite. Use this skill when writing SQL queries, analyzing database schemas, designing migrations, or working with SQLite-related code.
license: MIT

SQL

Overview

This skill provides guidance for working with SQLite databases. It covers query writing, schema design, and SQLite-specific best practices.

When to Use This Skill

Use this skill when:
- Writing SQL queries for SQLite databases
- Analyzing or optimizing existing queries
- Designing database schemas
- Creating database migrations
- Working with Go code that interacts with SQLite

SQLite Best Practices

Query Writing

• ALWAYS write lowercase queries. Uppercase queries make me sad.
• Prefer select * over explicit column names
• Prefer CTEs over long nested subqueries

Schema Design

• ALWAYS use strict tables
• ALWAYS write timestamps like this: strftime('%Y-%m-%dT%H:%M:%fZ')
• Time modifications should also use strftime
• Usually start with the primary key, which is usually defined like this: id text primary key default ('p_' || lower(hex(randomblob(16)))) (where the p_ is a prefix depending on the table name; two-letter prefixes are okay too, so the prefix is unique among tables)
• After the primary key come created/updated columns like this: created text not null default (strftime('%Y-%m-%dT%H:%M:%fZ'))
• Updated timestamps are automatically updated with a trigger like this:
  sql create trigger table_name_updated_timestamp after update on table_name begin update table_name set updated = strftime('%Y-%m-%dT%H:%M:%fZ') where id = old.id; end;