Select只有table的列名是继承SQL Server 2014中的table实现的

Question

我有一个问题，关于 select 仅 name 的 table 的列的 table 继承 table ] 在 SQL Server 2014 中。

即有四种类型的人（学生、教师、员工和主管) 并且所有这些都包含一个 id 用于从 Person table 继承的每种类型的人以及后来的 name 必须被 select 编辑和展示。

Table TypePerson:

CREATE TABLE [TypesPerson] 
(
    [typePersonID] INT NOT NULL,
    [typePerson] VARCHAR(50) NOT NULL,
    CONSTRAINT [PK_TypesPerson] PRIMARY KEY CLUSTERED ([typePersonID] ASC)
);

Insert 人的类型：

INSERT INTO [TypesPerson]
    SELECT 1,'students' UNION ALL
    SELECT 2,'teachers' UNION ALL
    SELECT 3,'employer' UNION ALL
    SELECT 4,'supervisor'

Table Person:

CREATE TABLE [Person] 
(
    [personID] INT IDENTITY (1, 1) NOT NULL ,
    [typePersonID] INT NOT NULL,
    CONSTRAINT [PK_Person] PRIMARY KEY CLUSTERED ([PersonID] ASC),
    CONSTRAINT [PK_UN_Person_Type] UNIQUE ([typePersonID])
);

Table Students 扩展 Person:

CREATE TABLE [Students] 
(
    [personID] INT IDENTITY (1, 1) NOT NULL ,
    [typePersonID] AS 1 PERSISTED, --type person = 1
    [name] VARCHAR(50) NOT NULL,
    CONSTRAINT [PK_Students] PRIMARY KEY CLUSTERED ([PersonID] ASC),
    CONSTRAINT [FK_Students] FOREIGN KEY ([typePersonID])
    REFERENCES [Person] ([typePersonID]),
);

Table Teachers 扩展 Person:

CREATE TABLE [Teachers] 
(
    [PersonID] INT IDENTITY (1, 1) NOT NULL ,
    [typePersonID] AS 2 PERSISTED, --type person = 2
    [name] VARCHAR(50) NOT NULL,
    CONSTRAINT [PK_Teachers ] PRIMARY KEY CLUSTERED ([PersonID] ASC),
    CONSTRAINT [FK_Teachers ] FOREIGN KEY ([typePersonID])
    REFERENCES [Person] ([typePersonID]),
);

Table Employers 扩展 Person:

CREATE TABLE [Employers] 
(
    [personID] INT IDENTITY (1, 1) NOT NULL ,
    [typePersonID] AS 3 PERSISTED, --type person = 3
    [name] VARCHAR(50) NOT NULL,
    CONSTRAINT [PK_Employers] PRIMARY KEY CLUSTERED ([PersonID] ASC),
    CONSTRAINT [FK_Employers] FOREIGN KEY ([typePersonID])
    REFERENCES [Person] ([typePersonID]),
);

Insert 数据创建类型为：

INSERT INTO [Person] ([typePersonID]) VALUES (1); --students
INSERT INTO [Person] ([typePersonID]) VALUES (2); --teachers
INSERT INTO [Person] ([typePersonID]) VALUES (3); --employer
INSERT INTO [Person] ([typePersonID]) VALUES (4); --supervisor

插入数据创建学生、教师和雇主：

INSERT INTO [Students]  ([name])  VALUES ('John'); --students
INSERT INTO [Teachers]  ([name])  VALUES ('Robert'); --teachers
INSERT INTO [Employers] ([name])  VALUES ('Ciara'); --employer
INSERT INTO [Supervisor] ([name]) VALUES ('Renata'); --supervisor

当我select只是使用这个脚本的名字

SELECT st.name, ts.name, es.name,  sp.name
FROM Person p
INNER JOIN Students   st ON p.personID= st.personID
INNER JOIN Teachers   ts ON p.personID= ts.personID
INNER JOIN Employers  es ON p.personID= es.personID
INNER JOIN Supervisor sp ON p.personID= sp.personID;

结果是

我想在 ListView 中显示所有这些 names 当我使用 <asp:SqlDataSource ID="SqlDataSource1" runat="server" /> 从数据库中获取数据并使用 <asp:ListView ID="ListView1" DataSourceID="SqlDataSource1" runat="server" /> 显示所有names在水平位置，如下图

有什么建议吗？

Answer 1

当你尝试这个时你会感到惊讶：

SELECT t.typePerson, sp.name
FROM Person p
INNER JOIN [TypesPerson] as t ON p.[typePersonID] = t.[typePersonID]
INNER JOIN Supervisor sp ON p.personID= sp.personID;

问题是你有两个问题：
1. 数据重复：typePersonID为同一个人存储了两次。
2. 你在Person中的personID与其他table中的personID没有任何关联。

本质上，最好只有 ONLY ONE Person table，只需在此处添加名称列即可。它会解决你所有的问题。

此外，而不是

CONSTRAINT [PK_UN_Person_Type] UNIQUE ([typePersonID])

放

CONSTRAINT [FK_Person_TypesPerson] FOREIGN KEY ([typePersonID])
REFERENCES [TypesPerson] ([typePersonID]),

Answer 2

通过使用 Pivot 你可以达到你的结果。但简单的方法你可以试试。

SELECT st.name Name
FROM Person p
INNER JOIN Students   st ON p.personID= st.personID

union
SELECT  ts.name Name
FROM Person p
INNER JOIN Teachers   ts ON p.personID= ts.personID
union

SELECT  es.name Name
FROM Person p
INNER JOIN Employers  es ON p.personID= es.personID
union

SELECT   sp.name Name
FROM Person p
INNER JOIN Supervisor sp ON p.personID= sp.personID

Select只有table的列名是继承SQL Server 2014中的table实现的

Select only the name of the column of the tables implemented by the inheritance of the table in SQL Server 2014

sql-server

asp.net

inheritance

listview

sqldatasource