如何在cordapp中提到H2数据库表的主键(How to mention the primary key of H2 database table in a cordapp)

如何在cordapp中提到H2数据库表的主键(How to mention the primary key of H2 database table in a cordapp)

我遵循cordapp示例代码并创建了IOU。 任何人都可以让我知道我在哪里可以看到它的H2数据库的主键？ 我如何更新以拥有复合键？

I am following the cordapp example code and created IOUs. Can anyone please let me know where can I see the primary key of its H2 database ? How Can I update to have a composite key ?

最满意答案

IOUState的数据库模式在IOUState定义： https ： //github.com/corda/cordapp-example/blob/release-V3/kotlin-source/src/main/kotlin/com/example/schema/IOUSchema.kt 。

所有状态模式都必须继承PersistentState 。 PersistentState将状态表的主键设置为PersistentStateRef实例的组合键。 PersistentStateRef结合了：

生成状态的事务的散列 该州的交易产出指数

从Corda 3开始，您不能将状态表更改为使用不同的主键。

The database schema for IOUState is defined here: https://github.com/corda/cordapp-example/blob/release-V3/kotlin-source/src/main/kotlin/com/example/schema/IOUSchema.kt.

All state schemas must subclass PersistentState. PersistentState sets the state table's primary key to a composite key which is an instance of PersistentStateRef. PersistentStateRef combines:

The hash of the transaction that generated the state The state's index in the outputs of that transaction

As of Corda 3, you cannot change the state's table to use a different primary key.