引用另一个子元素表的触发器

Question

在 SQL Server 中有两个表：Invoices (InvoiceId, Number, Date, Customer, TotalValue) 和 InvoicesElements (InvoiceId, Good, Qty, Value)。

每个事务在Invoices 中插入一行，在InvoicesElements 中插入一行/多行。

我需要在Invoices 表上设置一个触发器，当InvoicesElements 表中的Good 为“Bike”且客户为“ABC”时，该触发器将引发错误并回滚事务。

非常感谢任何帮助。

普热梅克

Answer 1

ALTER TABLE
        InvoicesElements
ADD CONSTRAINT
        CHK_GOOD
CHECK   (good <> 'Bike' OR good IS NULL)

更新：

CREATE TRIGGER
        TR_InvoicesElements_AIU
ON      InvoicesElements
AFTER   INSERT, UPDATE
AS
        IF EXISTS
                (
                SELECT  NULL
                FROM    INSERTED ie
                JOIN    Invoices inv
                ON      inv.id = ie.invoiceId
                WHERE   ie.good = 'bike'
                        AND inv.customer = 'ABC'
                )
                THROW 50000, 'Not sure why but you cannot sell bikes to ABC', 0
GO

CREATE TRIGGER
        TR_Invoices_AIU
ON      Invoices
AFTER   INSERT, UPDATE
AS
        IF EXISTS
                (
                SELECT  NULL
                FROM    InvoiceElements ie
                JOIN    INSERTED inv
                ON      inv.id = ie.invoiceId
                WHERE   ie.good = 'bike'
                        AND inv.customer = 'ABC'
                )
                THROW 50000, 'Not sure why but you cannot sell bikes to ABC', 0
GO