仅通过触发器对插入的行运行更新语句

Question

当添加到发票表[InvoiceTable] 时，我创建了一个触发器来更新发票记录上的自定义日期[Invoice.ContractStartDate]。

下面的触发器有效，但我希望它只为 插入的记录运行，并避免对 DateTimeCreated 使用 WHERE 子句。

对于Contract.Days <> ' '，我仍然需要WHERE 子句

这可以使用AFTER INSERT 或INSTEAD OF INSERT 吗？

 CREATE TRIGGER UpdateContractStartDate ON InvoiceTable 
 FOR INSERT AS
 UPDATE InvoiceTable
 SET InvoiceTable.ContractStartDate = InvoiceTable.InvoiceDate + Contract.Days
 FROM Contract
 INNER JOIN InvoiceTable
     ON InvoiceTable.ContractID = Contract.ContractID
 WHERE (CAST(InvoiceTable.DateTimeCreated AS DATE) = CAST(GETDATE() AS DATE))
 AND (Contract.Days <> '')

Answer 1

您没有提供有关表架构的任何信息，但假设您有一个唯一的键“Id”

典型的语法是

Update it set
  it.ContractStartDate = it.InvoiceDate + c.Days
from inserted i
join InvoiceTable it on it.Id=i.Id
join Contract c on c.ContactId=it.ContractId and c.Days <> ''