我正在为我们公司内部的资产管理系统工作。
系统允许用户在永久或临时的基础上登录/退出项目。
我正在研究系统的一些报道，并且在返回相关数据方面遇到了绊脚石。
所以我知道我需要在我的主查询中使用嵌套的Select TOP 1语句，但我无法使其工作。
主要查询如下：
SELECT [Asset-User].ID, [Asset-User].Asset_ID, [Assets].ID, [Assets].Signed_Out, [Assets].Asset_Tag_Serial_Num, [Assets].Name_Hostname, [Assets].Type_ID, [Asset_Type].ID, [Asset_Type].Name_Model, [Asset-User].User_ID, [Company_Users].ID, [Asset-User].Sign_Out_Date, [Asset-User].Return_Date, [Asset-User].[Perm_Signout?]
FROM [Asset-User], [Assets], [Asset_Type], [Company_Users]
WHERE ([User_ID] = '1') AND [Asset-User].Asset_ID = [Assets].ID AND [Assets].Type_ID = [Asset_Type].ID AND [Asset-User].User_ID = [Company_Users].ID AND [Assets].Signed_Out = '1'
因此，此查询将返回当前标记为“已签名”的所有内容，该内容已由用户1注销。
在这里的某个地方我需要在Asset-User.ID上添加一个嵌套的Select TOP 1，这样它才会返回标记为永久签名的项目，如果不是永久性的，那么它们最近已被用户1注销
这样只会给我一个当前分配给该用户的项目列表，如果其他人已经签署了该项目，则不会显示该资产
非常感谢任何帮助
根据要求下面的示例数据： https://docs.google.com/spreadsheets/d/1o4T6bsxyO-1dGE0-FUtWFboRupcq4o4V9i2Em0_BjyU/edit?usp=sharing
第一张表显示实际结果，第二张表显示了应该预期的结果
正如您将在此处看到的，此用户已多次注销了一些项目（这些项目可能最近未被此用户注销）
很难获得样本数据，但实际上列表中应该没有重复的Asset_ID，因为只应为每个Asset_ID显示最新的ID（与此相关的注销ID）。
这有帮助吗？
再次感谢
根据请求，这里是Schema构建代码，它将创建一个与
一起使用的示例数据库CREATE TABLE Asset_Type
([ID] int, [Global_ID] int, [Name_Model] varchar(30), [Description_Spec] varchar(54))
;
INSERT INTO Asset_Type
([ID], [Global_ID], [Name_Model], [Description_Spec])
VALUES
(1, 1, 'Dell Optiplex 3020', 'Windows 7 Professional, Intel Core i3 3.40GHz,4Gb RAM'),
(2, 3, 'Viewsonic VA2231wa', 'Viewsonic Widescreen Monitor'),
(3, 3, 'Samsung S24B150BL', 'Samsung LED 24" Widescreen Monitor')
;
CREATE TABLE Assets
([ID] int, [Asset_Tag_Serial_Num] varchar(29), [Type_ID] int, [Purchase_Date] varchar(10), [Purchase_Price] varchar(7), [Name_Hostname] varchar(36), [Signed_Out] int)
;
INSERT INTO Assets
([ID], [Asset_Tag_Serial_Num], [Type_ID], [Purchase_Date], [Purchase_Price], [Name_Hostname], [Signed_Out])
VALUES
(1, '0206', 1, '2013-11-29', '323.30', 'WS0206', 1),
(3, '0226', 2, NULL, NULL, 'Viewsonic VA2231wa - 0226', 1),
(4, '0204', 1, '2013-11-29', '323.00', 'WS0204', 1),
(5, '0205', 1, '2013-11-29', '323.00', 'WS0205', 1),
(6, '0108', 1003, NULL, NULL, 'Small Office Sat Nav', 1),
(7, '0092', 1004, NULL, NULL, 'Large Office Sat Nav', 1),
(8, 'GWC36-DHDBC-J2MXY-H2BGY-8C79G', 1005, '1900-01-01', '0.00', 'MS Office for WS0020', 1),
(9, '0020', 1006, '1900-01-01', '0.00', 'WS0020', 1),
(10, '0173', 2, '1900-01-01', '0.00', 'Viewsonic VA2231wa - 0173', 1),
(11, '0172', 1007, '1900-01-01', '0.00', 'Dell 19" Monitor 0172', 1),
(12, '00104926EC6B', 1008, '1900-01-01', '0.00', 'Shortel 230 - EC6B', 1),
(13, '0227', 1009, NULL, NULL, 'Blue - Yeti Mic', 0),
(14, '0221', 1, NULL, NULL, 'WS0221', 1),
(15, '0222', 1, '2013-11-29', '323.00', 'WS0222', 1),
(16, '0223', 1, NULL, NULL, 'WS0223', 1),
(17, '0220', 1, '2013-11-29', '323.00', 'WS0220', 1),
(18, '0217', 1, '2013-11-29', '323.00', 'WS0217', 1),
(19, '0218', 1, NULL, NULL, 'WS0218', 1),
(20, '0219', 1, '2013-11-29', '323.00', 'WS0219', 1),
(21, '0228', 2, NULL, NULL, 'Viewsonic VA2231wa - 0228', 1),
(22, '0229', 1010, NULL, NULL, 'Dell 19" Monitor 0229', 1),
(23, '00104931AA16', 1011, NULL, NULL, 'Shortel 115 - AA16', 1),
(24, '0093 - DYTJ18X4DJ8T', 1012, NULL, NULL, 'Office IPad 3', 1),
(25, '0095', 1013, '1900-01-01', '0.00', '320Gb External HDD', 1),
(26, '0071', 1014, NULL, NULL, '0071 - NEC Projector', 0),
(27, '0072', 1015, NULL, NULL, '0072 - Black Dell Projector', 0),
(28, '0073', 1016, '1900-01-01', '0.00', '0073 - Dell Projector', 0),
(29, '0230', 1017, '1900-01-01', '0.00', '0230 - Silver Dell Projector', 0),
(30, '0064', 1018, NULL, NULL, 'WS0064', 0),
(31, '0231', 1019, NULL, NULL, 'Freecom 1GB Pen - 0231', 1),
(47, '0165', 2, NULL, NULL, 'Viewsonic VA2231wa - 0165', 1),
(48, '0232', 1010, '1900-01-01', '0.00', 'Dell 19" Monitor 0232', 1),
(49, '0233', 1010, '1900-01-01', '0.00', 'Dell 19" Monitor 0233', 1),
(50, '0137', 1022, NULL, NULL, 'Viewsonic VA2248-LED - 0137', 1),
(51, '0234', 1010, '1900-01-01', '0.00', 'Dell 19" Monitor 0234', 1),
(52, '0235', 1010, '1900-01-01', '0.00', 'Dell 19" Monitor 0235', 1),
(53, '0134', 1010, NULL, NULL, 'Dell 19" Monitor 0134', 0),
(54, '0135', 1022, NULL, NULL, 'Viewsonic VA2248-LED - 0135', 1),
(55, '0236', 3, '1900-01-01', '0.00', 'Samsung S24B150BL - 0236', 1),
(56, '001049201D9A', 1008, '1900-01-01', '0.00', 'Shortel 230 - 1D9A', 1),
(57, '0010492015AE', 1008, '1900-01-01', '0.00', 'Shortel 230 - 15AE', 1),
(93, '0269', 1029, '1900-01-01', '0.00', 'TP-Link Switch - 0269', 0),
(94, '0058', 1030, NULL, NULL, 'WS0058', 1),
(95, '0270', 1031, NULL, NULL, 'MeetingRoom3', 1),
(96, '0243', 1032, NULL, NULL, 'MeetingRoom2', 1),
(97, '0271', 1027, NULL, NULL, 'Dynamode SW80010-D Switch - 0271', 0),
(123, '0281', 1045, '2014-07-18', '104.50', 'Philips 23.6" Monitor 0281', 0),
(124, '0282', 1045, '2014-07-18', '104.50', 'Philips 23.6" Monitor 0282', 1),
(125, '0283', 1045, '2014-07-18', '104.50', 'Philips 23.6" Monitor 0283', 0),
(126, '0284', 1045, '2014-07-18', '104.50', 'Philips 23.6" Monitor 0284', 1),
(127, '0285', 1045, '2014-07-18', '104.50', 'Philips 23.6" Monitor 0285', 1),
(128, '0286', 1045, '2014-07-18', '104.50', 'Philips 23.6" Monitor 0286', 1),
(129, '0287', 1045, '2014-07-18', '104.50', 'Philips 23.6" Monitor 0287', 1),
(143, '0280', 1, '2014-07-03', '403.80', 'WS0280', 1),
(144, '0296', 1, '2014-07-03', '403.80', 'WS0296', 1),
(145, '0297', 1, '2014-07-03', '403.80', 'WS0297', 1),
(146, '0298', 1, '2014-07-03', '403.80', 'WS0298', 1),
(147, '0299', 1, '2014-07-03', '403.80', 'WS0299', 1),
(148, '0052', 1036, '1900-01-01', '0.00', 'WS0052', 1),
(168, '0312', 1047, NULL, NULL, 'Epson White HD - 0312', 1),
(169, '0201', 1049, '1900-01-01', '0.00', 'Ipad 4 - 0201', 0),
(170, 'HP27J-2C496-83KXB-RGMX6-8QJQG', 1020, '1900-01-01', '0.00', 'MS Office for Jonny D', 1),
(171, '7N4QY-DFGWD-P6662-CFCHG-QYFP2', 1021, '1900-01-01', '0.00', 'MS Office for WS0215 (Simeon Laptop)', 1),
(172, '0140', 1022, '1900-01-01', '0.00', 'Viewsonic VA2248-LED - 0140', 1),
(198, '0109', 1037, '1900-01-01', '0.00', 'WS0109', 1),
(199, '0324', 1052, '1900-01-01', '0.00', 'Philips 23.6" Monitor 0324', 1)
;
CREATE TABLE [Asset-User]
([ID] int, [Asset_ID] int, [User_ID] int, [Sign_Out_Date] datetime, [Return_Date] datetime, [Perm_Signout] int)
;
INSERT INTO [Asset-User]
([ID], [Asset_ID], [User_ID], [Sign_Out_Date], [Return_Date], [Perm_Signout])
VALUES
(2, 1, 1, '2014-03-29 00:00:00', '2014-03-29 00:00:00', 0),
(3, 1, 1, '2014-03-29 00:00:00', '2014-03-29 00:00:00', 0),
(4, 1, 1, '2014-03-29 00:00:00', '2014-03-29 00:00:00', 0),
(5, 1, 1, '2014-03-29 00:00:00', '2014-03-29 00:00:00', 0),
(6, 1, 1, '2014-03-29 00:00:00', '2014-03-29 00:00:00', 0),
(7, 1, 1, '2014-03-29 00:00:00', '2014-03-29 00:00:00', 0),
(8, 1, 1, '2014-03-29 00:00:00', '2014-03-29 00:00:00', 0),
(9, 1, 1, '2014-03-29 00:00:00', '2014-03-29 00:00:00', 0),
(10, 1, 1, '2014-03-29 00:00:00', '2014-03-29 00:00:00', 0),
(11, 1, 1, '2014-03-29 00:00:00', '2014-03-29 00:00:00', 0),
(1002, 1, 1, '2014-04-01 00:00:00', '2014-04-01 00:00:00', 0),
(1003, 1, 1, '2014-01-01 00:00:00', '2014-01-01 00:00:00', 1)
;
CREATE TABLE Company_Users
([ID] int, [Name] varchar(14), [Domain_Username] varchar(14), [Dept] varchar(16), [Email] varchar(25), [DD_Ext] int, [Job_Title] varchar(30), [Deleted_Left] int)
;
INSERT INTO Company_Users
([ID], [Name], [Domain_Username], [Dept], [Email], [DD_Ext], [Job_Title], [Deleted_Left])
VALUES
(1, 'Neil Smithson', 'Neil.Smithson', '2nd Line Support', 'neil.smithson@dezrez.com', 3041, 'Second Line Support Technician', 0)
;
CREATE TABLE Global_Types
([ID] int, [Name] varchar(13), [Description] varchar(54))
;
INSERT INTO Global_Types
([ID], [Name], [Description])
VALUES
(1, 'PC', 'Desktop PC')
;
答案 0 :(得分：0)
这不是一个真正的答案，但会向您展示如何使用别名和（不是真正的）更新的连接样式来重写此查询。
SELECT au.ID
, au.Asset_ID
, a.ID
, a.Signed_Out
, a.Asset_Tag_Serial_Num
, a.Name_Hostname
, a.Type_ID
, at.ID
, at.Name_Model
, au.User_ID
, cu.ID
, au.Sign_Out_Date
, au.Return_Date
, au.[Perm_Signout?]
FROM [Asset-User] au
join Assets a on au.Asset_ID = a.ID
join Asset_Type at on a.Type_ID = at.ID
join Company_Users cu on au.User_ID = cu.ID
WHERE au.User_ID = '1'
AND a.Signed_Out = '1'