使用MSSQL：只是为了澄清
CustomerNumber Name
===================
1 David
2 Thomas
3 Mangold
4 Issac
------------------------------------------------------------
CustomerNumber State EffectiveDate
==================================
1 AL 01/01/2017
1 VA 06/01/2017
1 GA 02/01/2018
1 FL 10/01/2018
2 TX 01/01/2017
3 MA
4 IL 04/01/2015
CUSTOMER ORDERNo OrderDate
========================
1 1000 03/01/2017
2 1001 10/10/2017
1 1002 11/01/2017
3 1003 12/01/2017
4 1004 01/01/2018
1 1005 02/01/2018
1 1006 01/01/2019
我需要在订单日期获取所有包含客户详细信息和客户地址的订单。
SELECT T1.ORDERNo, T1.ORDERDATE, T1.CUSTOMER, T2.NAME, T3.STATE
FROM SALESORDER T1, CUSTOMER T2, CUSTOMERADDRESS T3
RIGHT JOIN(
SELECT CUSTOMER, MAX(EFFECTIVEDATE) FROM CUSTOMERADDRESS
--WHERE EFFECTIVEDATE <= T1.ORDERDATE
GROUP BY CUSTOMER)T4
ON T3.CUSTOMER = T4.CUSTOMER AND T3.EFFECTIVEDATE=T4.EFFECTIVEDATE
WHERE T1.CUSTOMER = T2.CUSTOMERNUMBER
AND T1.CUSTOMER = T3.CUSTOMERNUMBER
想了解如何在联接中进行比较，在联接中我将第一个表与第三个表进行比较。参见注释代码--WHERE EFFECTIVEDATE <= T1.ORDERDATE
如果删除注释的代码，则联接中的表无法引用外部表。
预期输出为：
CUSTOMER ORDERNo OrderDate CustomerName State
=============================================
1 1000 03/01/2017 David AL
2 1001 10/10/2017 Thomas TX
1 1002 11/01/2017 David VA
3 1003 12/01/2017 Mangold MA
4 1004 01/01/2018 Issac IL
1 1005 02/01/2018 David GA
1 1006 01/01/2019 David FL
sql小提琴http://sqlfiddle.com/#!18/9eecb中的表：
CREATE TABLE Customer
('CustomerNumber' int, 'CustomerName' varchar(30))
;
INSERT INTO Customer
('CustomerNumber', 'CustomerName')
VALUES
(1, 'David'),
(2, 'Thomas'),
(3, 'Mangold'),
(4, 'Issac')
;
CREATE TABLE CustomerAddress
('CustomerNumber' int, 'State' varchar(2), 'EffectiveDate' date)
;
INSERT INTO CustomerAddress
('CustomerNumber', 'State', 'EffectiveDate')
VALUES
(1, 'AL', 01/01/2017),
(1, 'VA', 06/01/2017),
(1, 'GA', 02/01/2018),
(1, 'FL', 10/01/2018),
(2, 'TX', 01/01/2017),
(3, 'MA',),
(4, 'IL', 04/01/2015)
;
CREATE TABLE SalesOrder
('CUSTOMER' int, 'ORDERNO' int, 'OrderDate' Date)
;
INSERT INTO SalesOrder
('CUSTOMER', 'ORDERNO', 'OrderDate')
VALUES
(1, 1000, 03/01/2017),
(2, 1001, 10/10/2017),
(1, 1002, 11/01/2017),
(3, 1003, 12/01/2017),
(4, 1004, 01/01/2018),
(1, 1005, 02/01/2018),
(1, 1006, 01/01/2019)
;
CREATE TABLE CustomerAddress
(`CustomerNumber` int, 'State' varchar(2), `EffectiveDate` date)
;
INSERT INTO CustomerAddress
(`CustomerNumber`, `State`, 'EffectiveDate')
VALUES
(1, 'AL', 01/01/2017),
(1, 'VA', 06/01/2017),
(1, 'GA', 02/01/2018),
(1, 'FL', 10/01/2018),
(2, 'TX', 01/01/2017),
(3, 'MA',),
(4, 'IL', 04/01/2015)
;
CREATE TABLE SalesOrder
(`CUSTOMER` int, 'ORDERNO' int, `OrderDate` Date)
;
INSERT INTO SalesOrder
(`CUSTOMER `, `ORDERNO`, 'OrderDate')
VALUES
(1, 1000, 03/01/2017),
(2, 1001, 10/10/2017),
(1, 1002, 11/01/2017),
(3, 1003, 12/01/2017),
(4, 1004, 01/01/2018),
(1, 1005, 02/01/2018),
(1, 1006, 01/01/2019)
;
“ sql server版本”
CREATE TABLE Customer
(CustomerNumber int, CustomerName varchar(30))
;
INSERT INTO Customer
(CustomerNumber, CustomerName)
VALUES
(1, 'David'),
(2, 'Thomas'),
(3, 'Mangold'),
(4, 'Issac');
;
CREATE TABLE CustomerAddress
(CustomerNumber int, State varchar(2), EffectiveDate date)
;
INSERT INTO CustomerAddress
(CustomerNumber, State, EffectiveDate)
VALUES
(1, 'AL', '01/01/2017'),
(1, 'VA', '06/01/2017'),
(1, 'GA', '02/01/2018'),
(1, 'FL', '10/01/2018'),
(2, 'TX', '01/01/2017'),
(4, 'IL', '04/01/2015')
;
INSERT INTO CustomerAddress
(CustomerNumber, State)
VALUES
(3, 'MA' )
;
CREATE TABLE SalesOrder
(CUSTOMER int, ORDERNO int, OrderDate Date)
;
INSERT INTO SalesOrder
(CUSTOMER, ORDERNO, OrderDate)
VALUES
(1, 1000, '03/01/2017'),
(2, 1001, '10/10/2017'),
(1, 1002, '11/01/2017'),
(3, 1003, '12/01/2017'),
(4, 1004, '01/01/2018'),
(1, 1005, '02/01/2018'),
(1, 1006, '01/01/2019')
;
问题：需要选择所有销售订单及其客户名称和客户地址。重要且棘手的部分是客户地址更改（基于销售订单的日期）。
-不完整查询的修改版本
SELECT T1.ORDERNo, T1.ORDERDATE, T1.CUSTOMER, T2.CustomerName, T3.STATE
FROM CUSTOMER T2, SALESORDER T1 INNER JOIN CUSTOMERADDRESS T3 ON T1.CUSTOMER = T3.CUSTOMERNUMBER
RIGHT JOIN(
SELECT CustomerNumber, MAX(EFFECTIVEDATE) as EffectiveDate4 FROM CUSTOMERADDRESS
--WHERE EFFECTIVEDATE < T1.ORDERDATE
GROUP BY CustomerNumber
--HAVING EFFECTIVEDATE < T1.ORDERDATE
) T4
ON T3.CustomerNumber = T4.CustomerNumber AND T3.EFFECTIVEDATE=T4.EffectiveDate4
WHERE T1.CUSTOMER = T2.CUSTOMERNUMBER
答案 0 :(得分：0)
外部申请应该可以解决您的问题。根据您的需求，您可以更改查询。
SELECT T1.ORDERNo, T1.ORDERDATE, T1.CUSTOMER, T2.NAME, T3.STATE
FROM SALESORDER T1, CUSTOMER T2, CUSTOMERADDRESS T3
OUTER APPLY(
SELECT CUSTOMER, MAX(EFFECTIVEDATE) FROM CUSTOMERADDRESS
WHERE EFFECTIVEDATE <= T1.ORDERDATE
AND T3.CUSTOMER = CUSTOMER )T4
WHERE T1.CUSTOMER = T2.CUSTOMERNUMBER
AND T1.CUSTOMER = T3.CUSTOMERNUMBER
AND T3.EFFECTIVEDATE = T4.EFFECTIVEDATE