使用此项：

ISNULL(SUBSTRING(REPLACE((select ',' FName as 'data()' from NameList for xml path('')), ' ,',', '), 2, 300), '') 'MyList'

其中“300”可以是任何宽度，考虑到您认为将显示的最大项目数。

SQL Server 2005或更高版本

CREATE TABLE dbo.Students
(
    StudentId INT
    , Name VARCHAR(50)
    , CONSTRAINT PK_Students PRIMARY KEY (StudentId)
);

CREATE TABLE dbo.Subjects
(
    SubjectId INT
    , Name VARCHAR(50)
    , CONSTRAINT PK_Subjects PRIMARY KEY (SubjectId)
);

CREATE TABLE dbo.Schedules
(
    StudentId INT
    , SubjectId INT
    , CONSTRAINT PK__Schedule PRIMARY KEY (StudentId, SubjectId)
    , CONSTRAINT FK_Schedule_Students FOREIGN KEY (StudentId) REFERENCES dbo.Students (StudentId)
    , CONSTRAINT FK_Schedule_Subjects FOREIGN KEY (SubjectId) REFERENCES dbo.Subjects (SubjectId)
);

INSERT dbo.Students (StudentId, Name) VALUES
    (1, 'Mary')
    , (2, 'John')
    , (3, 'Sam')
    , (4, 'Alaina')
    , (5, 'Edward')
;

INSERT dbo.Subjects (SubjectId, Name) VALUES
    (1, 'Physics')
    , (2, 'Geography')
    , (3, 'French')
    , (4, 'Gymnastics')
;

INSERT dbo.Schedules (StudentId, SubjectId) VALUES
    (1, 1)        --Mary, Physics
    , (2, 1)    --John, Physics
    , (3, 1)    --Sam, Physics
    , (4, 2)    --Alaina, Geography
    , (5, 2)    --Edward, Geography
;

SELECT
    sub.SubjectId
    , sub.Name AS [SubjectName]
    , ISNULL( x.Students, '') AS Students
FROM
    dbo.Subjects sub
    OUTER APPLY
    (
        SELECT
            CASE ROW_NUMBER() OVER (ORDER BY stu.Name) WHEN 1 THEN '' ELSE ', ' END
            + stu.Name
        FROM
            dbo.Students stu
            INNER JOIN dbo.Schedules sch
                ON stu.StudentId = sch.StudentId
        WHERE
            sch.SubjectId = sub.SubjectId
        ORDER BY
            stu.Name
        FOR XML PATH('')
    ) x (Students)
;

在SQL Server中实现这一点的一种方法是将表内容返回为XML（对于XML原始），将结果转换为字符串，然后用“，”替换标记。

我并没有做过任何关于性能的分析，因为我的列表中只有不到10项，但在查看了30多个答案后，我感到很惊讶，我仍然对已经给出的类似答案进行了修改，类似于对单个组列表使用COALESCE，甚至不必设置我的变量（无论如何默认为NULL），并且它假设我的源数据表中的所有条目都是非空的：

DECLARE @MyList VARCHAR(1000), @Delimiter CHAR(2) = ', '
SELECT @MyList = CASE WHEN @MyList > '' THEN @MyList + @Delimiter ELSE '' END + FieldToConcatenate FROM MyData

我确信COALENCE内部使用了相同的想法。让我们希望微软不会在我身上改变这一点。

在MySQL中，有一个函数GROUP_CONCATT（），它允许您连接多行的值。例子：

SELECT 1 AS a, GROUP_CONCAT(name ORDER BY name ASC SEPARATOR ', ') AS people 
FROM users 
WHERE id IN (1,2,3) 
GROUP BY a

首先，您应该声明一个表变量并用表数据填充它，然后，使用WHILE循环，逐个选择行并将其值添加到nvarchar（max）变量中。

    Go
    declare @temp table(
        title nvarchar(50)
    )
    insert into @temp(title)
    select p.Title from dbo.person p
    --
    declare @mainString nvarchar(max)
    set @mainString = '';
    --
    while ((select count(*) from @temp) != 0)
    begin
        declare @itemTitle nvarchar(50)
        set @itemTitle = (select top(1) t.Title from @temp t)
    
        if @mainString = ''
        begin
            set @mainString = @itemTitle
        end
        else
        begin
            set @mainString = concat(@mainString,',',@itemTitle)
        end
    
        delete top(1) from @temp
    
    end
    print @mainString