Question

我想创建一个触发器和一个执行以下操作的函数：每次在表SalesOrderDetail中插入一个新行时，该函数从表SalesOrderHeader中找到相应的CustomerID，然后它将+1添加到Customer表中相应的number_of_sales

SalesOrderDetail
+---------+-------------------------+
| SalesOrderID  | SalesOrderDetailID |
+---------+-------------------------+
|     value1    |       value4       |
|     value1    |       value5       |
|     value2    |       value6       |
|     value3    |       value7       |
|     value3    |       value8       |
|     value4    |       value9       |
+---------+-------------------------+


SalesOrderHeader
+---------+-----------------+
| SalesOrderID | CustomerID |
+---------+-----------------+
|   value1    |   value10   |
|   value2    |   value11   |
|   value3    |   value12   |
|   value4    |   value13   |
+---------+-----------------+



Customer
+---------+--------------------+
| CustomerID | Number_of_sales |
+---------+--------------------+
|   value10   |      value14   |
|   value11   |      value15   |
|   value12   |      value16   |
|   value13   |      value17   |
+---------+--------------------+

代码如下：

CREATE OR REPLACE FUNCTION new_order_detail()
RETURNS trigger AS
$BODY$
BEGIN
    DROP TABLE IF EXISTS CustomerInfo;
    CREATE TEMP TABLE CustomerInfo AS
        SELECT* FROM(SELECT CustomerID FROM(
    SELECT * from SalesOrderHeader
    WHERE  SalesOrderHeader.SalesOrderID = (SELECT SalesOrderID FROM SalesOrderDetail ORDER BY SalesOrderID DESC limit 1))AS Last_Entry) AS Common_Element;




    IF CustomerInfo.CustomerID = Customer.CustomerID THEN
    UPDATE Customer
    SET number_of_items = number_of_items + 1;
    END IF;



END;
$BODY$ LANGUAGE plpgsql;


DROP TRIGGER IF EXISTS new_order ON SalesOrderDetail;

CREATE TRIGGER new_order
    AFTER INSERT OR UPDATE ON SalesOrderDetail
    FOR EACH ROW EXECUTE PROCEDURE new_order_detail();

当我在SalesOrderDetail表中插入内容时，出现以下错误：

PL / pgSQL函数new_order_detail（）在SQL语句第3行错误：   表＆＃34; customerinfo＆＃34;缺少FROM子句条目第1行：选择   CustomerInfo.CustomerID = Customer.CustomerID                  ^ QUERY：SELECT CustomerInfo.CustomerID = Customer.CustomerID CONTEXT：PL / pgSQL function new_order_detail（）   IF的第12行   **********错误**********

错误：缺少FROM-clause条目表＆＃34; customerinfo＆＃34; SQL状态：   42P01上下文：PL / pgSQL函数new_order_detail（）IF中的第12行

我做错了什么？对不起，英语不是我的母语。

Answer 1

首先，您需要注意区分大小写的pgsql。如果您没有明确使用“”，则会将所有内容转换为小写。

接下来，您的程序应该是这样的：

select CustomerID from SalesOrderHeader where SalesOrderDetail.SalesOrderID = SalesOrderHeader.SalesOrderID into custID; UPDATE Customer SET number_of_items = number_of_items + 1 where CustomerID = custID ;

错误：运行函数

1 个答案: