📚 Inheritance — 继承

--- name: inheritance-mapping-selector description: | 为任何需要持久化到关系数据库的 OO 继承体系，选择正确的 ORM 继承策略——Single Table Inheritance（STI）、Class Table Inheritance（joined table / Multi-Table Inheritance）或 Concrete Table Inheritance（table per class）。 在以下提问时使用：“我该用哪种继承映射？”、“单表 vs 连接表继承”、“STI vs CTI vs table per class”、“Hibernate 继承策略 SINGLE_TABLE vs JOINED vs TABLE_PER_CLASS”、“@Inheritance JPA”、“Rails STI vs multi-table inheritance”、“Django model inheritance type”、“如何在数据库中映射继承”、“数据库设计中的继承”、“鉴别列继承”、“ORM 多态查询性能”、“多态表设计”、“table per class 继承权衡”、“joined 继承 vs 单表”、“继承模式设计”。 适用于新 schema 设计、ORM 配置或遗留 schema 重构。基于六个权衡维度为策略指路：多态读时是否 join、列空间浪费、FK 约束可执行性、即席查询可读性、重构影响、多态查询成本。识别何时因分支差异需用 Inheritance Mappers 混合策略。将策略映射为惯用 ORM 配置：Hibernate/JPA @Inheritance(SINGLE_TABLE/JOINED/TABLE_PER_CLASS)、Rails STI type 列、Django Multi-Table Inheritance vs abstract base。输出继承映射决策记录，含 schema 草图与 ORM 配置片段。 version: 1.0.0 homepage: https://github.com/bookforge-ai/bookforge-skills/tree/main/books/patterns-of-enterprise-application-architecture/skills/inheritance-mapping-selector metadata: {"openclaw":{"emoji":"📚","homepage":"https://github.com/bookforge-ai/bookforge-skills"}} status: draft source-books:

• id: patterns-of-enterprise-application-architecture

title: "Patterns of Enterprise Application Architecture" authors: ["Martin Fowler", "David Rice", "Matthew Foemmel", "Edward Hieatt", "Robert Mee", "Randy Stafford"] chapters: [3, 12] domain: software-architecture tags: ["inheritance-mapping", "orm", "persistence", "database-design", "design-patterns", "single-table-inheritance", "class-table-inheritance", "concrete-table-inheritance", "polymorphic-query", "object-relational-mapping", "fowler-peaa", "hibernate", "joined-table-inheritance"] depends-on: [] execution: tier: 2 mode: hybrid inputs:

• type: document

description: "OO 继承体系描述（类名、字段分布、深度）、所用 ORM/框架、多态读取是否频繁、schema 约束（FK 强制、外部消费者、遗留 schema）。" tools-required: [Read, Write] tools-optional: [Grep] mcps-required: [] environment: "任意 agent 环境。可基于架构文档、ORM 模型文件、schema 文件或书面领域描述工作。有代码库访问可提高精度，非必需。" discovery: goal: "给出具体继承映射建议，含 ORM 配置、SQL schema 草图与迁移路径。" tasks: - "收集继承体系结构（深度、字段分布、抽象 vs 具体类）" - "识别多态查询频率及是否常在超类级别查找" - "评估子类字段差异度（字段相近→STI；差异大→CTI 或 Concrete）" - "确定 FK 约束需求与外部消费者要求" - "按六个权衡维度打分，选定主策略" - "检查是否因分支差异需混合策略" - "将建议映射为团队 ORM 惯用法（Hibernate、Rails、Django 等）" - "输出继承映射决策记录，含 schema 草图与 ORM 配置片段" audience: roles: ["software-architect", "senior-backend-engineer", "tech-lead", "database-designer"] experience: "intermediate" when_to_use: triggers: - "为新 OO 领域模型设计含继承的 schema" - "在 Hibernate/JPA 中选择 @Inheritance 策略注解" - "决定 Rails 用 STI 还是手动多表方案" - "发现 STI 表过宽、NULL 过多" - "发现 CTI join 在高读接口造成性能问题" - "重构未刻意设计继承的遗留 schema" - "记录持久化继承的架构决策" prerequisites: [] not_for:

• "选择数据源访问模式（Active Record vs Data Mapper）——见 data-source-pattern-selector"
• "完整结构映射模式（关联、集合、嵌入值）——见 object-relational-structural-mapping-guide"
• "查询优化或索引设计——见 sql-query-optimizer"