# Infra Bc Query Generator > Use when generating CQRS read-side query infrastructure (query DTO/Mapper/Impl) for a bounded context, with optional app query ports and projection write paths. - Skill: `tomevault-io/infra-bc-query-generator` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/infra-bc-query-generator` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/infra-bc-query-generator/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: DevOps & Infra - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/infra-bc-query-generator --- # Infra BC Query Generator ## Overview Generates CQRS/read-side query infrastructure for a bounded context—lightweight query DTOs, mappers, and implementations that keep read paths separated from write-side aggregates. **REQUIRED:** Follow `GENERATOR_SKILL_STRUCTURE.md`. Variables in `VARIABLES.md`. Templates: See `references/templates.md`. ## When to Use - Creating read-side query implementations under: - `{{basePackage}}.infra.query.{{bcName}}.dto` - `{{basePackage}}.infra.query.{{bcName}}.mapper` - `{{basePackage}}.infra.query.{{bcName}}.impl` - Supporting application query services (`{{basePackage}}.app.{{bcName}}.query.*`) - Adding projection write paths alongside read endpoints for new read models ### Don't use when - Implementing write-side aggregate persistence—use `infra-bc-repository-generator` - Generating standalone PO/Mapper for write tables—use `infra-mybatis-po-mapper-generator` - Building web-layer DTOs for API responses—use `adapter-web-controller-generator` ## Inputs Required - Business context name (`{{bcName}}`) - Query use-case name (what the query returns) - Output DTO shape (fields + paging) - Storage source: - existing write table(s) or dedicated read model/projection - Whether an app query port is needed: - If app wants an abstraction, generate `{{basePackage}}.app.{{bcName}}.port.*` (optional by design) ## Outputs - Query DTO: - `{{infraModuleDir}}/src/main/java/{{basePackagePath}}/infra/query/{{bcName}}/dto/.java` - Mapper: - `.../infra/query/{{bcName}}/mapper/.java` - Implementation: - `.../infra/query/{{bcName}}/impl/.java` (implements app port when used) - When the feature introduces or changes a read model/projection table, also generate projection write components in infra query (`*ProjectionMapper`, `*ProjectionPortImpl`) so read/write paths are both present. - Optional app port + app query DTO: - `{{appModuleDir}}/src/main/java/{{basePackagePath}}/app/{{bcName}}/port/.java` - `{{appModuleDir}}/src/main/java/{{basePackagePath}}/app/{{bcName}}/query/dto/.java` - Pagination DTOs (`PageQuery`, `PageResult`) in `app/common/query/dto/` (generated once, reused) - Tests: - Unit tests for mapping logic - `*IT` if query SQL is non-trivial or relies on indexes/constraints ## Naming & Packaging - Query DTOs are infra-only; do not expose to domain. - App query DTOs (if any) should be app-owned and stable. - Prefer `*QueryMapper` and `*QueryPortImpl`. ## Implementation Rules - Query paths should not load full aggregates; return lightweight DTOs. - Keep SQL/persistence details in query mapper. - If app defines a query port, infra implementation must only depend on app types (DTOs/ports), not adapter types. - Time boundary logic in infra query impl must use injected `AppClock`; do not call `Instant.now()` directly. - Do not deliver query-only code for new read models: projection write path and query read path must be completed in the same slice. ## Reference Implementations - Package rules: - `{{infraModuleDir}}/src/main/java/{{basePackagePath}}/infra/query/package-info.java` - `{{infraModuleDir}}/src/main/java/{{basePackagePath}}/infra/query/{{bcName}}/impl/package-info.java` - App port guidance: - `{{appModuleDir}}/src/main/java/{{basePackagePath}}/app/{{bcName}}/port/package-info.java` ## Tests - Prefer unit tests for mapping; use `*IT` for SQL correctness. - Add unit tests for query-service normalization logic (default page/size/limit clamping) when such logic exists. ## Common Mistakes | Mistake | Why It Happens | Fix | |---------|---------------|-----| | Reusing infra query DTOs as web DTOs | Shortcut to avoid creating adapter-layer DTOs | Adapter owns web DTOs; infra query DTOs stay in infra | | Depending on domain aggregates in read models | Loading full aggregates for convenience | Query paths return lightweight DTOs; never load aggregates | | Shipping read endpoints without projection write path | Delivering query-only without upsert/update logic | Complete both projection write and query read in the same slice | | Calling `Instant.now()` directly in query impl | Forgetting testability requirements | Inject `AppClock` and use it for all time boundary logic | ## Phase Commit Gate Before committing generated/updated code: - Ensure compile and unit tests pass (minimum: `mvn -q clean test`). - If DB behavior/schema changes are involved, run `mvn -q clean verify` to execute `*IT`. - Invoke `requesting-code-review` for the intended commit scope and resolve Critical/Important findings. - Prefer one focused commit per phase/slice (do not batch unrelated changes). ## Integration - **Called by:** `scaffold-router`, `dev-workflow-ddd-implementation-workflow` - **Pairs with:** `infra-flyway-migration-generator`, `infra-mybatis-po-mapper-generator`, `infra-it-db-generator`, `app-port-generator`, `adapter-web-controller-generator` --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/ryan-alexander-zhang) — claim your Tome and manage your conversions.