java TIMESTAMP 列的 H2 数据库默认值
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H2 database default value of TIMESTAMP column
提问by DominikM
I am writing integration tests with H2 database. My database (generated) initialization include this script (because generated join table does not have this column):
我正在使用 H2 数据库编写集成测试。我的数据库（生成）初始化包括这个脚本（因为生成的连接表没有这个列）：
ALTER TABLE INT_USR ADD IU_INSDTTM TIMESTAMP DEFAULT NOW();
This is how I create records:
这就是我创建记录的方式：
Integration integrationOne = createIntegration(firstId, "FIRST");
Integration integrationTwo = createIntegration(secondId, "SECOND");
flushAndClear();
userService.logRecentIntegration(integrationOne.getId(), user.getId());
flushAndClear();
userService.logRecentIntegration(integrationTwo.getId(), user.getId()); //1
The method logRecentIntegrations(.., ..) just calls the DAO and the dao does this:
方法 logRecentIntegrations(.., ..) 只是调用 DAO 并且 dao 执行以下操作：
Query query = entityManager.createNativeQuery(
"INSERT INTO INT_USR (USR_ID, INT_ID) VALUES (?, ?)");
query.setParameter(1, userId)
.setParameter(2, integrationId);
query.executeUpdate();
Later in my test:
后来在我的测试中：
Query query = entityManager.createNativeQuery(
"SELECT * FROM INT_USR ORDER BY IU_INSDTTM");
List resultList = query.getResultList();
When I debug this test in resultList there are two records (correct) but they have same timestamp. Even when I inserted a breakpoint on line marked //1 and waited a while - so the time gap between inserts would be significant. (Thread.sleep - same result)
当我在 resultList 中调试此测试时，有两条记录（正确）但它们具有相同的时间戳。即使我在标记为 //1 的行上插入了一个断点并等待了一段时间 - 所以插入之间的时间间隔会很明显。（Thread.sleep - 结果相同）
I tried to modify the SQL script to
我试图将 SQL 脚本修改为
ALTER TABLE INT_USR ADD IU_INSDTTM TIMESTAMP DEFAULT CURRENT_TIMESTAMP;
But with same result. Why both results have same timestamp?
但结果相同。为什么两个结果都有相同的时间戳？
回答by Thomas Mueller
As documented, the function CURRENT_TIMESTAMPalways returns the same value within a transaction. This behavior matches other databases, for example PostgreSQL.
如文档所述，函数 CURRENT_TIMESTAMP始终在事务中返回相同的值。此行为与其他数据库匹配，例如 PostgreSQL。
回答by Jeremy D
You may add the following annotation to your test to disable transactions.
您可以在测试中添加以下注释以禁用事务。
@Transaction(propagation = Propagation.NEVER)
@Transaction(propagation = Propagation.NEVER)
Note: That annotation comes from Spring and there may be something else for the environment that you are running within.
注意：该注解来自 Spring，并且您在其中运行的环境可能还有其他内容。
