PostgreSQL and Drizzle ORM

Match database work to the project's installed API and deployment context. The user's explicit instructions take precedence over this skill's guidelines.

Establish the database contract

Use the relevant schema/query, migration history, and requested behavior as input. For Drizzle code, inspect installed drizzle-orm/drizzle-kit versions and the driver; for SQL, establish the PostgreSQL version when a version-specific feature matters.

The references cover PostgreSQL 17/18 and distinguish Drizzle's 0.x relations() API from the v1 defineRelations() API. Do not mix them or infer the installed API from an npm dist-tag. When the version is unknown, use imports/lockfiles or ask for the missing version before giving version-dependent code.

Keep changes consistent

• Declare database foreign keys separately from ORM relation metadata. Match nullability, uniqueness, and delete behavior to the actual relationship.
• Use the transaction handle for every statement in that transaction; a query through the outer connection can escape it.
• Diagnose slow queries from plans and workload evidence. Evaluate indexes on referencing columns; PostgreSQL does not create them automatically.
• Generate and inspect migration SQL for schema changes. Preserve applied migration history; use a new migration for subsequent changes.
• Establish the target before applying migrations or push. Authoring or reviewing SQL does not itself require executing it against a database. Continue execution when the user has already authorized that target and action.
• Treat EXPLAIN ANALYZE as query execution, including writes. Use a suitable test target or non-executing plan when execution is outside the task.