name: Database description: Standards for database interaction, connection pooling, and repository patterns in Golang. metadata: labels: [golang, database, sql, postgres, repository] triggers: files: ['internal/adapter/repository/**'] keywords: [database, sql, postgres, gorm, sqlc, pgx]

Golang Database Standards

Priority: P0 (CRITICAL)

Principles

• Prefer Raw SQL/Builders over ORMs: Go structs map well to SQL. ORMs (GORM) can obscure performance. Recommended: sqlc (type-safe SQL generation).
• Repository Pattern: Abstract DB access behind interfaces in internal/port/ (e.g., UserRepository).
• Connection Pooling: Always configure SetMaxOpenConns, SetMaxIdleConns, SetConnMaxLifetime.
• Transactions: Logic requiring ACID MUST use transactions. Pass context.Context everywhere.

Drivers

• PostgreSQL: jackc/pgx (Prefer pgx/v5 for performance and features).
• MySQL: go-sql-driver/mysql.
• SQLite: mattn/go-sqlite3 or modernc.org/sqlite (pure Go).

Anti-Patterns

• Global DB Connection: Do not use global var db *sql.DB. Inject it.
• Ignoring Context: Always use db.QueryContext or db.ExecContext to handle timeouts.
• Leaking Rows: ALWAYS defer rows.Close() and check rows.Err().

References

• Repository Pattern Implementation
• Connection Tuning