Write efficient and secure database queries following best practices for SQL injection prevention, N+1 query optimization, and performance for PostgreSQL (Bun.sql, Prisma, Supabase) and Firestore. Use this skill when writing or modifying database queries, implementing data fetching logic, working with ORMs (Prisma, TypeORM, Entity Framework), using Bun.sql native driver, querying Firestore collections, or implementing caching strategies. Apply when working on service files (services/*.ts, repositories/*.ts, *Service.cs), query builder implementations, data access layers, or any code that fetches or manipulates data. This skill ensures parameterized queries to prevent SQL injection (never interpolate user input), eager loading to prevent N+1 problems, selective column fetching (no SELECT *), strategic indexing on WHERE/JOIN/ORDER BY columns, transactions for related operations, query timeouts for performance, caching expensive queries, prepared statements with Bun.sql for repeated queries, and query-driven mod
Installation
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
Write efficient and secure database queries following best practices for SQL injection prevention, N+1 query optimization, and performance for PostgreSQL (Bun.sql, Prisma, Supabase) and Firestore. Use this skill when writing or modifying database queries, implementing data fetching logic, working with ORMs (Prisma, TypeORM, Entity Framework), using Bun.sql native driver, querying Firestore collections, or implementing caching strategies. Apply when working on service files (services/*.ts, repositories/*.ts, *Service.cs), query builder implementations, data access layers, or any code that fetches or manipulates data. This skill ensures parameterized queries to prevent SQL injection (never interpolate user input), eager loading to prevent N+1 problems, selective column fetching (no SELECT *), strategic indexing on WHERE/JOIN/ORDER BY columns, transactions for related operations, query timeouts for performance, caching expensive queries, prepared statements with Bun.sql for repeated queries, and query-driven modeling for Firestore to avoid complex OR queries.
Backend Queries
When to use this skill:
When writing new database queries or data fetching operations
When working with ORM query builders (Prisma, TypeORM, Sequelize, Entity Framework)
When using Bun.sql native PostgreSQL driver for high-performance queries
When implementing service layer methods that query databases
When working on repository pattern implementations
When writing raw SQL queries for complex operations
When optimizing slow queries or addressing N+1 query problems
When implementing eager loading or query joins
When adding database indexes to improve query performance
When wrapping related operations in database transactions
When implementing caching strategies for frequently-accessed data
When setting query timeouts to prevent long-running queries
When working on files that contain data access logic (services/.ts, repositories/.ts, Service.cs, models/.py)
When querying Firestore collections and designing queries based on data model
When using prepared statements for repeated queries in Bun.sql
This Skill provides Claude Code with specific guidance on how to adhere to coding standards as they relate to how it should handle backend queries.
Instructions
For details, refer to the information provided in this file:
backend queries
