数据库每日一题 （4）存储过程

题目

解答

SUM(t1.销售数量*t1.销售单价) --SUM(销售数量*销售单价) 也正确

t1.商品号 = t2.商品号

year(t1.销售时间) --year(销售时间) 也正确

t2.类别 = @lb

解析

建表

if not exists(SELECT name FROM SYS.DATABASES WHERE name = 'SALES')
CREATE DATABASE SALES

USE SALES

if exists(SELECT name FROM sys.objects WHERE name = 'SELL')
DROP TABLE SELL

if exists(SELECT name FROM sys.objects WHERE name = 'COMMODITY')
DROP TABLE COMMODITY

CREATE TABLE COMMODITY
(
NO INT PRIMARY KEY,
NAME CHAR(10) NOT NULL  UNIQUE,
CATEGORY CHAR(10) NOT NULL,
COST FLOAT NOT NULL
)
CREATE TABLE SELL
(
NO INT FOREIGN KEY REFERENCES COMMODITY(NO),
TIME DATETIME NOT NULL,
QUANTITY INT NOT NULL,
PRICE FLOAT NOT NULL,
PROFIT FLOAT 
)

插入值

INSERT INTO COMMODITY
VALUES 
	(1,'冰红茶','饮料', 1.5),
	(2,'方便面','食品',0.5),
	(3,'矿泉水','饮料',0.8)

创建触发器

练习上一次所学的触发器知识，在题目表格之外，新增一列此次交易利润。通过创建触发器，提供购买的商品号与数量，计算此次交易的利润并填入表格。

注意：此表与题目表格区别在此

并且，通过阅读文章SQL Server 触发器批量数据行处理，做到了批量处理交易数据。

计算商品利润触发器

USE SALES
IF EXISTS(SELECT * FROM DBO.SYSOBJECTS WHERE ID = OBJECT_ID(N'[DBO].[COUNTPROFIT]') AND OBJECTPROPERTY(ID, N'ISTRIGGER') = 1)
DROP TRIGGER COUNTPROFIT
GO

--批量插入触发
CREATE TRIGGER COUNTPROFIT 
	ON SELL
	INSTEAD OF INSERT
AS
BEGIN 
	INSERT INTO SELL
		SELECT NO,TIME,QUANTITY,PRICE,(QUANTITY*(SELECT COST 
			FROM COMMODITY C
			WHERE C.NO = I.NO)) AS PROFIT
		FROM inserted I
END;

插入数据测试

INSERT INTO SELL
VALUES
	--商品号，日期，数量，价格，获利（由触发器计算）
	(1,GETDATE(),2,3, null ),
	(2,GETDATE(),2,1, null ),
	(1,GETDATE(),2,3, null ),
	(3,GETDATE(),2,1, null )

存储过程（完整答案）

USE SALES

IF EXISTS(SELECT name FROM SYS.objects WHERE NAME ='p_TotalProfit')
DROP PROC p_TotalProfit
GO
CREATE PROC p_TotalProfit
@lb char(10)
AS
SELECT NAME AS 商品名, (SELECT SUM(QUANTITY*PRICE)
				FROM SELL t1
				WHERE t1.NO=t2.NO and year(t1.time)=year(GETDATE())) AS 销售总金额
FROM COMMODITY t2
WHERE t2.CATEGORY = @lb
GO 

测试结果

源码地址

GitHub仓库