Sql server 更改所有行的列值

我有以下表格：

create table dbo.Files (
  Id int identity not null constraint PK_Files_Id primary key (Id),
  Content varbinary (max) null,
  Name nvarchar (280) null
)

create table dbo.BookFiles (
  BookId int not null, 
  FileId int not null, 
    constraint PK_BookFiles_Id primary key (BookId, FileId)
)

alter table dbo.BookFiles
add constraint FK_BookFiles_BookId foreign key (BookId) references Books(Id) on delete cascade on update cascade,
    constraint FK_BookFiles_FileId foreign key (FileId) references Files(Id) on delete cascade on update cascade;

一些数据如下：

BookId    FileId    Id   Name    Content
1         1         1    image
1         2         1    image
2         3         2    image
3         4         3    image

有些书有两个图像（BookdId=1），有些书有一个图像（BookId=2,3）

我需要将所有文件的名称重命名为：

“image1”表示书籍的第一个图像（最低文件ID）

“image2”用于书籍的第二个图像（如果存在）

我知道如何更新所有行中的值：

UPDATE files SET name = "image1";  

但我不知道如何设置“image1”和“image2”

---

有人能帮我吗？

从您的问题中提取数据，下面的代码片段将能够根据您的需要提供结果-

declare @t table (BookId int,    FileId int,    Id int,   Name  nvarchar(280),   Content varbinary (max))
insert into @t values
(1,         1,         1,    'image',null),
(1,         2,         1,    'image',null),
(2,         3,         2,    'image',null),
(3,         4,         3,    'image',null)
;with cte as
(
select *, ROW_NUMBER() OVER(PARTITION BY BookId ORDER BY BookId) rn
from @t
)
select BookId,FileId,Id,(Name+cast(rn as nvarchar(1))) AS Name,Content from cte

使用子查询筛选出具有多个图像的书籍

update t set t.name = case when fileid = 1 then 'ima1' else 'ima2' end 
from table t
where bookid in (
    select bookid from table
    group by bookid
    having  count(*) > 1
)

为了更新所有图像文件，您可以使用排名函数

行号（）

您可以尝试使用
CTE
。它不特定于只有2个相同id的图像，它将适用于任何数量的图像，您有一本书，数字将相应地追加

    ;WITH CT AS
    (
      SELECT BOOKID, FILEID, ROW_NUMBER() OVER 
        (PARTITION BY BookId ORDER BY BOOKID) AS RN , NAME 
       FROM BookFiles BF INNER JOIN Files F ON F.Id = BF.FileId
    )
    UPDATE CT
    SET NAME= 'image' + CAST(RN AS VARCHAR(10))

注意：您对
CTE
所做的更新将级联到源表

    ;WITH CT AS
    (
      SELECT BOOKID, FILEID, ROW_NUMBER() OVER 
        (PARTITION BY BookId ORDER BY BOOKID) AS RN , NAME 
       FROM BookFiles BF INNER JOIN Files F ON F.Id = BF.FileId
    )
    UPDATE CT
    SET NAME= 'image' + CAST(RN AS VARCHAR(10))