Install
Terminal · npx$
npx skills add https://github.com/obra/superpowers --skill brainstormingWorks with Paperclip
How Golang Database fits into a Paperclip company.
Golang Database drops into any Paperclip agent that handles this kind of work. Assign it to a specialist inside a pre-configured PaperclipOrg company and the skill becomes available on every heartbeat — no prompt engineering, no tool wiring.
S
SaaS FactoryPaired
Pre-configured AI company — 18 agents, 18 skills, one-time purchase.
$27$59
Explore packSource file
SKILL.md243 linesExpandCollapse
---name: golang-databasedescription: "Comprehensive guide for Go database access. Covers parameterized queries, struct scanning, NULLable column handling, error patterns, transactions, isolation levels, SELECT FOR UPDATE, connection pool, batch processing, context propagation, and migration tooling. Use this skill whenever writing, reviewing, or debugging Golang code that interacts with PostgreSQL, MariaDB, MySQL, or SQLite. Also triggers for database testing or any question about database/sql, sqlx, pgx, or SQL queries in Golang. This skill explicitly does NOT generate database schemas or migration SQL."user-invocable: truelicense: MITcompatibility: Designed for Claude Code or similar AI coding agents, and for projects using Golang.metadata: author: samber version: "1.1.2" openclaw: emoji: "🗄️" homepage: https://github.com/samber/cc-skills-golang requires: bins: - go install: []allowed-tools: Read Edit Write Glob Grep Bash(go:*) Bash(golangci-lint:*) Bash(git:*) Agent AskUserQuestion--- **Persona:** You are a Go backend engineer who writes safe, explicit, and observable database code. You treat SQL as a first-class language — no ORMs, no magic — and you catch data integrity issues at the boundary, not deep in the application. **Modes:** - **Write mode** — generating new repository functions, query helpers, or transaction wrappers: follow the skill's sequential instructions; launch a background agent to grep for existing query patterns and naming conventions in the codebase before generating new code.- **Review/debug mode** — auditing or debugging existing database code: use a sub-agent to scan for missing `rows.Close()`, un-parameterized queries, missing context propagation, and absent error checks in parallel with reading the business logic. > **Community default.** A company skill that explicitly supersedes `samber/cc-skills-golang@golang-database` skill takes precedence. # Go Database Best Practices Go's `database/sql` provides a solid foundation for database access. Use `sqlx` or `pgx` on top of it for ergonomics — never an ORM. When using sqlx or pgx, refer to the library's official documentation and code examples for current API signatures. ## Best Practices Summary 1. **Use sqlx or pgx, not ORMs** — ORMs hide SQL, generate unpredictable queries, and make debugging harder2. Queries MUST use parameterized placeholders — NEVER concatenate user input into SQL strings3. Context MUST be passed to all database operations — use `*Context` method variants (`QueryContext`, `ExecContext`, `GetContext`)4. `sql.ErrNoRows` MUST be handled explicitly — distinguish "not found" from real errors using `errors.Is`5. Rows MUST be closed after iteration — `defer rows.Close()` immediately after `QueryContext` calls6. NEVER use `db.Query` for statements that don't return rows — `Query` returns `*Rows` which must be closed; if you forget, the connection leaks back to the pool. Use `db.Exec` instead7. **Use transactions for multi-statement operations** — wrap related writes in `BeginTxx`/`Commit`8. **Use `SELECT ... FOR UPDATE`** when reading data you intend to modify — prevents race conditions9. **Set custom isolation levels** when default READ COMMITTED is insufficient (e.g., serializable for financial operations)10. **Handle NULLable columns** with pointer fields (`*string`, `*int`) or `sql.NullXxx` types11. Connection pool MUST be configured — `SetMaxOpenConns`, `SetMaxIdleConns`, `SetConnMaxLifetime`, `SetConnMaxIdleTime`12. **Use external tools for migrations** — golang-migrate or Flyway, never hand-rolled or AI-generated migration SQL13. **Batch operations in reasonable sizes** — not row-by-row (too many round trips), not millions at once (locks and memory)14. **Never create or modify database schemas** — a schema that looks correct on toy data can create hotspots, lock contention, or missing indexes under real production load. Schema design requires understanding of data volumes, access patterns, and production constraints that AI does not have15. **Avoid hidden SQL features** — do not rely on triggers, views, materialized views, stored procedures, or row-level security in application code ## Library Choice | Library | Best for | Struct scanning | PostgreSQL-specific || --- | --- | --- | --- || `database/sql` | Portability, minimal deps | Manual `Scan` | No || `sqlx` | Multi-database projects | `StructScan` | No || `pgx` | PostgreSQL (30-50% faster) | `pgx.RowToStructByName` | Yes (COPY, LISTEN, arrays) || GORM/ent | **Avoid** | Magic | Abstracted away | **Why NOT ORMs:** - Unpredictable query generation — N+1 problems you cannot see in code- Magic hooks and callbacks (BeforeCreate, AfterUpdate) make debugging harder- Schema migrations coupled to application code- Learning the ORM API is harder than learning SQL, and the abstraction leaks ## Parameterized Queries ```go// ✗ VERY BAD — SQL injection vulnerabilityquery := fmt.Sprintf("SELECT * FROM users WHERE email = '%s'", email) // ✓ Good — parameterized (PostgreSQL)var user Usererr := db.GetContext(ctx, &user, "SELECT id, name, email FROM users WHERE email = $1", email) // ✓ Good — parameterized (MySQL)err := db.GetContext(ctx, &user, "SELECT id, name, email FROM users WHERE email = ?", email)``` ### Dynamic IN clauses ```goquery, args, err := sqlx.In("SELECT * FROM users WHERE id IN (?)", ids)if err != nil { return fmt.Errorf("building IN clause: %w", err)}query = db.Rebind(query) // adjust placeholders for your drivererr = db.SelectContext(ctx, &users, query, args...)``` ### Dynamic column names Never interpolate column names from user input. Use an allowlist: ```goallowed := map[string]bool{"name": true, "email": true, "created_at": true}if !allowed[sortCol] { return fmt.Errorf("invalid sort column: %s", sortCol)}query := fmt.Sprintf("SELECT id, name, email FROM users ORDER BY %s", sortCol)``` For more injection prevention patterns, see the `samber/cc-skills-golang@golang-security` skill. ## Struct Scanning and NULLable Columns Use `db:"column_name"` tags for sqlx, `pgx.CollectRows` with `pgx.RowToStructByName` for pgx. Handle NULLable columns with pointer fields (`*string`, `*time.Time`) — they work cleanly with both scanning and JSON marshaling. See [Scanning Reference](./references/scanning.md) for examples of all approaches. ## Error Handling ```gofunc GetUser(id string) (*User, error) { var user User err := db.GetContext(ctx, &user, "SELECT id, name FROM users WHERE id = $1", id) if err != nil { if errors.Is(err, sql.ErrNoRows) { return nil, ErrUserNotFound // translate to domain error } return nil, fmt.Errorf("querying user %s: %w", id, err) } return &user, nil}``` or: ```gofunc GetUser(id string) (u *User, exists bool, err error) { var user User err := db.GetContext(ctx, &user, "SELECT id, name FROM users WHERE id = $1", id) if err != nil { if errors.Is(err, sql.ErrNoRows) { return nil, false, nil // "no user" is not a technical error, but a domain error } return nil, false, fmt.Errorf("querying user %s: %w", id, err) } return &user, true, nil}``` ### Always close rows ```gorows, err := db.QueryContext(ctx, "SELECT id, name FROM users")if err != nil { return fmt.Errorf("querying users: %w", err)}defer rows.Close() // prevents connection leaks for rows.Next() { // ...}if err := rows.Err(); err != nil { // always check after iteration return fmt.Errorf("iterating users: %w", err)}``` ### Common database error patterns | Error | How to detect | Action || --- | --- | --- || Row not found | `errors.Is(err, sql.ErrNoRows)` | Return domain error || Unique constraint | Check driver-specific error code | Return conflict error || Connection refused | `err != nil` on `db.PingContext` | Fail fast, log, retry with backoff || Serialization failure | PostgreSQL error code `40001` | Retry the entire transaction || Context canceled | `errors.Is(err, context.Canceled)` | Stop processing, propagate | ## Context Propagation Always use the `*Context` method variants to propagate deadlines and cancellation: ```go// ✗ Bad — no context, query runs until completion even if client disconnectsdb.Query("SELECT ...") // ✓ Good — respects context cancellation and timeoutsdb.QueryContext(ctx, "SELECT ...")``` For context patterns in depth, see the `samber/cc-skills-golang@golang-context` skill. ## Transactions, Isolation Levels, and Locking For transaction patterns, isolation levels, `SELECT FOR UPDATE`, and locking variants, see [Transactions](./references/transactions.md). ## Connection Pool ```godb.SetMaxOpenConns(25) // limit total connectionsdb.SetMaxIdleConns(10) // keep warm connections readydb.SetConnMaxLifetime(5 * time.Minute) // recycle stale connectionsdb.SetConnMaxIdleTime(1 * time.Minute) // close idle connections faster``` For sizing guidance and formulas, see [Database Performance](./references/performance.md). ## Migrations Use an external migration tool. Schema changes require human review with understanding of data volumes, existing indexes, foreign keys, and production constraints. Recommended tools: - [golang-migrate](https://github.com/golang-migrate/migrate) — CLI + Go library, supports all major databases- [Flyway](https://flywaydb.org/) — JVM-based, widely used in enterprise environments- [Atlas](https://atlasgo.io/) — modern, declarative schema management Migration SQL should be written and reviewed by humans, versioned in source control, and applied through CI/CD pipelines. ## Avoid Hidden SQL Features Do not rely on triggers, views, materialized views, stored procedures, or row-level security in application code — they create invisible side effects and make debugging impossible. Keep SQL explicit and visible in Go where it can be tested and version-controlled. ## Schema Creation **This skill does NOT cover schema creation.** AI-generated schemas are often subtly wrong — missing indexes, incorrect column types, bad normalization, or missing constraints. Schema design requires understanding data volumes, access patterns, query profiles, and business constraints. Use dedicated database tooling and human review. ## Deep Dives - **[Transactions](./references/transactions.md)** — Transaction boundaries, isolation levels, deadlock prevention, `SELECT FOR UPDATE`- **[Testing Database Code](./references/testing.md)** — Mock connections, integration tests with containers, fixtures, schema setup/teardown- **[Database Performance](./references/performance.md)** — Connection pool sizing, batch processing, indexing strategy, query optimization- **[Struct Scanning](./references/scanning.md)** — Struct tags, NULLable column handling, JSON marshaling patterns ## Cross-References - → See `samber/cc-skills-golang@golang-security` skill for SQL injection prevention patterns- → See `samber/cc-skills-golang@golang-context` skill for context propagation to database operations- → See `samber/cc-skills-golang@golang-error-handling` skill for database error wrapping patterns- → See `samber/cc-skills-golang@golang-testing` skill for database integration test patterns ## References - [database/sql tutorial](https://go.dev/doc/database/)- [sqlx](https://github.com/jmoiron/sqlx)- [pgx](https://github.com/jackc/pgx)- [golang-migrate](https://github.com/golang-migrate/migrate)