mysql - MySql 触发器中的 NEW.some_column 的 SQL Server 模拟是什么？

Question

这是我第一次处理 SQL Server 触发器。

在此之前，我为 MySql Server 编写了几乎相同的触发器，现在尝试为 SQL Server 重新编写代码。我修好了所有东西，但现在不明白它想要什么？我们还能如何访问刚刚插入的行的某些列，就像在 MySQL 中可能的那样 - NEW.some_field？

CREATE TRIGGER AntiCloneInsert ON dbo.user_item FOR INSERT AS

DECLARE @acc_id INT;
DECLARE @items_count INT;

IF (NEW.item_type in (select item_type from dbo.forbidden_item_types))
BEGIN
    select @items_count = count(item_type) from dbo.user_item where item_type = NEW.item_type and warehouse = NEW.warehouse
    IF (@items_count > 1)
    BEGIN
        select @acc_id = account_id from dbo.user_data where char_id = NEW.char_id
        update lin2db.dbo.user_account set block_flag2 = 1 where uid = @acc_id
    END
END

我尝试创建此触发器但出现此类错误:

Msg 4104, Level 16, State 1, Procedure AntiCloneInsert, Line 6
The multi-part identifier "NEW.item_type" could not be bound.

Msg 4104, Level 16, State 1, Procedure AntiCloneInsert, Line 8
The multi-part identifier "NEW.item_type" could not be bound.

Msg 4104, Level 16, State 1, Procedure AntiCloneInsert, Line 8
The multi-part identifier "NEW.warehouse" could not be bound.

Msg 4104, Level 16, State 1, Procedure AntiCloneInsert, Line 11
The multi-part identifier "NEW.char_id" could not be bound.

Answer 1

SQL Server 没有new 和old 记录。相反，它有 inserted 和 deleted 表。这意味着可以使用集合操作(​​或循环，如果您真的愿意)来完成逻辑。

我认为下面是等价逻辑:

CREATE TRIGGER AntiCloneInsert ON dbo.user_item FOR INSERT AS
BEGIN   
    update ua
        set block_flag2 = 1
        from ua join
             dbo.user_data ud
             on ua.uid = ud.account_id join
             inserted i
             on ud.char_id = i.char_id join
             dbo.forbidden_item_types it
             on it.item_type = i.item_type
         where  (select count(it2.item_type)
                 from dbo.user_item it2
                 where it2.item_type = i.item_type and
                       it2.warehouse = i.warehouse
                ) > 1;
END