name: infra-mybatis-po-mapper-generator description: "Generates MyBatis/MyBatis-Plus PO + Mapper patterns for infra, choosing BaseMapper vs SQL mapping with clear tradeoffs."

Infra MyBatis PO/Mapper Generator

Follow .codex/skills/GENERATOR_SKILL_STRUCTURE.md.

Templates: See references/templates.md.

Use For

• PO under {{basePackage}}.infra.**.po
• Mapper under {{basePackage}}.infra.**.mapper

Inputs Required

• Table name + columns + constraints (from Flyway migration)
• Access pattern: pure CRUD vs claim/lease/conditional updates
• MyBatis vs MyBatis-Plus choice (see rules)

Outputs

• .../infra/.../po/<XxxPO>.java
• .../infra/.../mapper/<XxxMapper>.java
• Optional IT when using locking or conditional updates

Naming & Packaging

• PO: <TableName>PO (or <Context><Entity>PO)
• Mapper: <TableName>Mapper
• Keep under BC-first infra.repository.{{bcName}}.* or feature packages like infra.event.outbox.*.

Implementation Rules

• Prefer MyBatis-Plus BaseMapper<T> when CRUD is standard and constraints are simple.
• Use explicit SQL (annotations/XML) when:
  • conditional update/claim semantics are needed (lock owner predicates)
  • FOR UPDATE SKIP LOCKED is required
  • multi-step atomic transitions must be encoded precisely
• Keep PO focused on persistence; convert to domain/app types at boundaries.

Reference Implementations

• {{infraModuleDir}}/src/main/java/{{basePackagePath}}/infra/event/outbox/po/OutboxEventPO.java
• {{infraModuleDir}}/src/main/java/{{basePackagePath}}/infra/event/outbox/mapper/OutboxEventMapper.java
• {{infraModuleDir}}/src/main/java/{{basePackagePath}}/infra/repository/workflow/mapper/WorkflowStepMapper.java

Tests

• Add *IT for any mapper using FOR UPDATE SKIP LOCKED or status transitions.

Pitfalls

• Using BaseMapper for claim/update flows that need precise predicates (race conditions).
• PO field names mismatching SQL columns (migration drift).

Output checklist

• Mapper methods include necessary predicates (status/lock/lease)
• PO fields match migration columns exactly
• Integration test for critical mappers if DB semantics involved