Sql server 在轴中使用两列
我已经发布了这个问题并得到了答案,但是现在我需要在结果集中再做一件事 我的Sql server 在轴中使用两列,sql-server,tsql,pivot,Sql Server,Tsql,Pivot,我已经发布了这个问题并得到了答案,但是现在我需要在结果集中再做一件事 我的User表有一个Register列,其中包含公司人力资源部门中的用户ID。当用户具有MemberType=0时,我需要返回此Register列。我该怎么做 以下是创建示例数据库的脚本: CREATE TABLE Project ( Id int, Name VARCHAR(50), CONSTRAINT PK_Project PRIMARY KEY (Id)); CREATE TABLE [User] (
User
表有一个Register
列,其中包含公司人力资源部门中的用户ID。当用户具有MemberType=0
时,我需要返回此Register
列。我该怎么做
以下是创建示例数据库的脚本:
CREATE TABLE Project (
Id int,
Name VARCHAR(50),
CONSTRAINT PK_Project PRIMARY KEY (Id));
CREATE TABLE [User] (
Id int,
Name VARCHAR(50),
Register int,
CONSTRAINT PK_User PRIMARY KEY (Id));
CREATE TABLE ProjectMember (
Project_Id int,
User_Id int,
MemberType tinyint,
CONSTRAINT PK_ProjectMember PRIMARY KEY(Project_Id, User_Id),
CONSTRAINT FK_ProjectMember_Project FOREIGN KEY(Project_Id) REFERENCES Project(Id),
CONSTRAINT FK_ProjectMember_User FOREIGN KEY(User_Id) REFERENCES [User](Id));
INSERT INTO Project(Id, Name) VALUES(1, 'Project 1');
INSERT INTO Project(Id, Name) VALUES(2, 'Project 2');
INSERT INTO Project(Id, Name) VALUES(3, 'Project 3');
INSERT INTO Project(Id, Name) VALUES(4, 'Project 4');
INSERT INTO Project(Id, Name) VALUES(5, 'Project 5');
INSERT INTO Project(Id, Name) VALUES(6, 'Project 6');
INSERT INTO Project(Id, Name) VALUES(7, 'Project 7');
INSERT INTO [User](Id, Name, Register) VALUES(1, 'User 1', 23498374);
INSERT INTO [User](Id, Name, Register) VALUES(2, 'User 2', 96849887);
INSERT INTO [User](Id, Name, Register) VALUES(3, 'User 3', 6546884);
INSERT INTO [User](Id, Name, Register) VALUES(4, 'User 4', 8489848);
INSERT INTO [User](Id, Name, Register) VALUES(5, 'User 5', 4684854);
INSERT INTO [User](Id, Name, Register) VALUES(6, 'User 6', 4849888);
INSERT INTO [User](Id, Name, Register) VALUES(7, 'User 7', 84884446);
INSERT INTO [User](Id, Name, Register) VALUES(8, 'User 8', 77554454);
INSERT INTO [User](Id, Name, Register) VALUES(9, 'User 9', 77853997);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(1, 1, 0);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(1, 2, 1);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(1, 3, 2);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(1, 4, 2);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(1, 5, 2);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(3, 6, 0);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(3, 5, 1);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(4, 3, 0);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(4, 4, 1);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(4, 5, 2);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(5, 7, 0);
INSERT INTO ProjectMember(Project_Id, User_Id, MemberType) VALUES(6, 8, 1);
我必须像这样返回数据:
ProjectId | ProjectName | UserType0 (Name) | UserType0 (Register) | UserType1 (Name)
项目名称:用户类型0(名称),用户类型0(登记),用户类型1(名称)< P>我将考虑使用条件聚合方法而不是使用<代码> PIVOT < /Cord>运算符。 我认为这个查询应该满足您的要求:
SELECT
ProjectID = P.Id,
ProjectName = P.Name,
[UserType0 (Name)] = MAX(CASE WHEN MemberType = 0 THEN u.Name END),
[UserType0 (Register)] = MAX(CASE WHEN MemberType = 0 THEN Register END),
[UserType1 (Name)] = MAX(CASE WHEN MemberType = 1 THEN u.Name END)
FROM Project AS P
LEFT JOIN ProjectMember AS PM ON P.Id = PM.Project_Id
LEFT JOIN [User] AS U ON PM.User_Id = U.Id
GROUP BY P.Id, P.Name
根据您的样本数据,结果将是:
ProjectID ProjectName UserType0 (Name) UserType0 (Register) UserType1 (Name)
1 Project 1 User 1 23498374 User 2
2 Project 2 NULL NULL NULL
3 Project 3 User 6 4849888 User 5
4 Project 4 User 3 6546884 User 4
5 Project 5 User 7 84884446 NULL
6 Project 6 NULL NULL User 8
7 Project 7 NULL NULL NULL
只是出于好奇。你是说这种方法更好,还是说使用
pivot
操作符无法获得相同的结果?@juliannuessilvaoliveira使用pivot
可能是可行的,但我认为它最终会涉及使用聚合函数,对我来说,我使用的方法感觉更简单。这当然只是我的意见。