- Add H2 database and MyBatis Test dependencies
- Create complete schema-test.sql with all 9 tables
- Create application-test.yml with proper configuration
- Create MapperIntegrationTest with 3 real database tests
- Fix ApplicationContext loading issues (bean conflicts, circular dependencies)
- Add missing fields: order_id, remark, member_count
- Fix data types: gender INT instead of VARCHAR
Test Results:
✓ Test 1: Batch query 30 athletes in 21ms (1 query vs 30 queries)
✓ Test 2: Complete N+1 optimization in 78ms (4 queries vs 30+ queries)
✓ Test 3: Performance comparison - batch is faster than N+1
This proves our Phase 4 optimization works in real database!
Total tests: 469 (466 + 3 integration tests)
All tests passing!
