breeze - 是否可以通过另一个表的导航属性设置主外键？

Question

我有一个表 TaxReturn，它有一个 ProcessID 的主外键，它映射到 ProcessID 的流程表主键。我需要将 TaxReturn 的 ProcessID 设置为 Process 表的 ProcessID。如何使用 Breeze 执行此操作，这样我就不会保存两次并两次往返数据库？

Answer 1

May I rephrase?

• You have two tables, Process and TaxReturn
• Process has a 1..(0,1) association with TaxReturn
• ProcessID is the PK of Process
• ProcessID is the PK of TaxReturn and is also the FK to the parent Process

Thus a Process can have zero or one TaxReturns.

If you create and save aProcess and TaxReturn at the same time (assuming the camelCase NamingConvention):

var process = manager.createEntity('Process');
var taxReturn = manager.createEntity('TaxReturn', {ProcessID: process.processID});
// ... fill them in
return manager.saveChanges(); // Breeze saves them together in a single transaction.

If you add a TaxReturn to an existing Process:

var taxReturn = manager.createEntity('TaxReturn', {ProcessID: existingProcess.processID});
// ... fill them in
return manager.saveChanges(); // saves the new TaxReturn.