autojanet/skills/understand/languages/sql.md

SQL Language Prompt Snippet

Key Concepts

• DDL (Data Definition): CREATE TABLE, ALTER TABLE, DROP TABLE for schema management
• DML (Data Manipulation): SELECT, INSERT, UPDATE, DELETE for data operations
• Normalization: Organizing tables to reduce redundancy through 1NF, 2NF, 3NF relationships
• Foreign Keys: REFERENCES constraints enforcing referential integrity between tables
• Indexes: CREATE INDEX for query performance optimization on frequently queried columns
• Migrations: Numbered, sequential schema changes applied in order for version control
• Transactions: BEGIN/COMMIT/ROLLBACK for atomic multi-statement operations
• Views: Named queries (CREATE VIEW) providing virtual tables for complex joins
• Stored Procedures: Server-side functions for encapsulating business logic in the database
• Constraints: NOT NULL, UNIQUE, CHECK, DEFAULT for data integrity rules

Notable File Patterns

• migrations/*.sql — Numbered migration files (e.g., 001_create_users.sql, 002_add_orders.sql)
• schema.sql — Full database schema definition (often generated from migrations)
• seeds/*.sql — Seed data for development and testing environments
• *.up.sql / *.down.sql — Reversible migration pairs (up applies, down reverts)
• init.sql — Database initialization script for Docker or fresh setup
• procedures/*.sql — Stored procedure definitions

Edge Patterns

• SQL migration files migrates the tables they create or alter
• Schema definition files defines_schema for the ORM models or data layer code that reads them
• Table definitions create implicit related edges between tables connected by foreign keys
• Seed files depends_on the migration files that create the tables they populate

Summary Style

"Database migration creating the users table with email, name, and authentication columns." "Schema definition with N tables covering user management, orders, and payment processing." "Seed data populating N tables with development fixtures for testing."