Question

我想要实现的是我有一个叫做订单的表。我想在我的订单table.i上执行before insert触发器。我想捕获执行INSERT到表的人的用户名。一个名为info的表，其中包含用户。

这是我的代码

create table orders
(
  order_id int,
  quantity  int,
  cost int,
  total_cost int,
  created_date datetime,
  created_by varchar(20)
)

create  trigger beforeInsertdata
 before insert
  on orders
 for each row
  declare 
 v_username varchar2(10);
begin
 -- Find username of person performing INSERT into table

    SELECT user INTO v_username
    FROM info;
 -- Update create_date field to current system date
    :new.create_date := sysdate;
 -- Update created_by field to the username of the person performing the INSERT
    :new.created_by := v_username;

END;

--user information--
create table info
(
  userid int ,
  user_name varchar(10)
)

insert into info values(1,'vivek')
select * from info

Answer 1

基本上，触发器分为两种主要类型： -

1）触发后（触发器）

2）取代触发器

，触发器的语法是

  CREATE TRIGGER trigger_name ON table_name 
  [FOR|AFTER|INSTEAD OF] [INSERT|UPDATE|DELETE]

  AS

  //your code goes here   

  GO

注意：用于INSERT | UPDATE命令的FOR关键字，其中为AFTER USED FOR DELETE命令。

Answer 2

很难说出你真正要做的事情。我已修改了您的代码示例，以便它可以在SQL2K5上运行，并对您希望如何使用连接的用户帐户做出一些假设。

CREATE TABLE orders (
  order_id int,
  quantity int,
  cost int,
  total_cost int,
  created_date datetime,
  created_by varchar(20)
);

CREATE TABLE info (
  userid int,
  user_name varchar(10)
);

INSERT INTO info
VALUES (1, 'vivek');

SELECT *
FROM info;

CREATE TRIGGER orders_InsteadOfInsert ON orders
INSTEAD OF INSERT AS BEGIN
  SET NOCOUNT ON;

  -- varchar(10) is to match your table, but probably should be larger
  DECLARE @CurrentUser VarChar(10);
  SELECT @CurrentUser = SYSTEM_USER;

  IF (@CurrentUser NOT IN (SELECT user_name FROM info)) BEGIN
    -- consider using an identity column for the key instead of this
    INSERT INTO info (userid, user_name)
    SELECT
      ISNULL((SELECT MAX(userid) FROM info), 0) + 1,
      @CurrentUser;
  END;

  INSERT INTO orders (order_id, quantity, cost, total_cost, created_date, created_by)
  SELECT
    INS.order_id,
    INS.quantity,
    INS.cost,
    INS.total_cost,
    GETDATE(),
    @CurrentUser
  FROM INSERTED INS;
END;

我试图执行前插入触发器，但我得到sql错误

2 个答案: