我想執行之前的插入觸發器，但我得到的SQL錯誤

Question

我想實現的是我有一個表，稱爲訂單。 我想在我的訂單table.i上執行之前的插入觸發器，我想捕獲執行INSERT的人的 用戶名到表中。 一張表包含用戶的信息。

這是我的代碼

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，觸發器被分爲兩種主要類型： -

1）之後觸發（對於觸發器）

2），而不是觸發器

和觸發語法是

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

    AS 

    //your code goes here 

    GO 

注意：FOR關鍵字用於INSERT | UPDATE命令，其中用作DELETE命令後使用。

Answer 2

很難說出你真正想要做什麼。我已經修改了你的代碼示例，以便它可以在SQL2K5上工作，並且假設你想要使用連接的用戶帳戶。

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;