纸上得来终觉浅，绝知此事要躬行
这次的主角是 @Transactional(propagation= Propagation.MANDATORY )；调用者方法必须存在事务，不然报出IllegalTransactionStateException 异常
继续验证
1、InsertUser 使用mandatory ，InsertCuser不加注解
InsertUser 报异常
org.springframework.transaction.IllegalTransactionStateException: No existing transaction found for transaction marked with propagation 'mandatory'
2、InsertUser 不加注解 ，InsertCuser使用mandatory
InsertUser 非事务方式执行
InsertCuser报异常
org.springframework.transaction.IllegalTransactionStateException: No existing transaction found for transaction marked with propagation 'mandatory'
3、InsertUser 使用 mandatory，InsertCuser 使用requires_new
InsertUser 报异常
org.springframework.transaction.IllegalTransactionStateException: No existing transaction found for transaction marked with propagation 'mandatory'
4、InsertUser 使用 requires_new，InsertCuser 使用mandatory
InsertUser 将事务传播给InsertCuser ，两者使用同一事务
5、InsertUser 使用 mandatory，InsertCuser 使用not_supported
InsertUser 报异常
org.springframework.transaction.IllegalTransactionStateException: No existing transaction found for transaction marked with propagation 'mandatory'
6、InsertUser 使用not_supported ，InsertCuser 使用mandatory
InsertUser 以非事务方式执行，InsertCuser 报错
org.springframework.transaction.IllegalTransactionStateException: No existing transaction found for transaction marked with propagation 'mandatory'
7、InsertUser 使用 mandatory，InsertCuser 使用never
InsertUser 报异常
org.springframework.transaction.IllegalTransactionStateException: No existing transaction found for transaction marked with propagation 'mandatory'
8、InsertUser 使用 never，InsertCuser 使用 mandatory
InsertUser 非事务状态执行，InsertCuser报异常
org.springframework.transaction.IllegalTransactionStateException: No existing transaction found for transaction marked with propagation 'mandatory'
9 、InsertUser 使用 mandatory，InsertCuser 使用 nested
InsertUser 报异常
org.springframework.transaction.IllegalTransactionStateException: No existing transaction found for transaction marked with propagation 'mandatory'
10、InsertUser 使用 nested ，InsertCuser 使用 mandatory
InsertUser 将事务传播给InsertCuser ，两者使用同一事务
大总结
| 实验 | InsertUser 调用者
|
InsertCuser 被调用者
|
结果 |
|---|---|---|---|
| 1 | mandatory | 不加 | InsertUser 报异常IllegalTransactionStateException |
| 2 | 不加 | mandatory | InsertUser 非事务方式执行，InsertCuser报异常 IllegalTransactionStateException |
| 3 | mandatory | requires_new | InsertUser 报异常IllegalTransactionStateException |
| 4 | requires_new | mandatory | InsertUser 将事务传播给InsertCuser ，两者使用同一事务 |
| 5 | mandatory | not_supported | InsertUser 报异常IllegalTransactionStateException |
| 6 | not_supported | mandatory | InsertUser 以非事务方式执行，InsertCuser 报错IllegalTransactionStateException |
| 7 | mandatory | never | InsertUser 报异常IllegalTransactionStateException |
| 8 | never | mandatory | InsertUser 以非事务方式执行，InsertCuser 报错IllegalTransactionStateException |
| 9 | mandatory | nested | InsertUser 报异常IllegalTransactionStateException |
| 10 | nested | mandatory | InsertUser 将事务传播给InsertCuser ，两者使用同一事务 |
