---
description: "SQL and database migration conventions: naming, safety, parameterized queries, indexing, Postgres"
globs: ["**/*.sql", "**/migrations/**", "**/Migrations/**"]
---
# SQL / Migrations

- Use lowercase for SQL keywords (or match project convention); snake_case for table/column names
- Every migration must be reversible (include DOWN/rollback)
- Never rename tables or columns without explicit confirmation — prefer additive changes
- Use parameterized queries; never concatenate user input into SQL
- Add indexes for columns used in WHERE, JOIN, ORDER BY
- Use transactions for multi-step data changes
- Include `NOT NULL` constraints by default; explicitly allow `NULL` only when needed
- Name constraints explicitly: `pk_table`, `fk_table_column`, `idx_table_column`
- Test migrations against a copy of production schema before applying
