从 sql 表数据生成 URL

Question

考虑下表：

EntityPictures表：

Id  EntityId    PictureId  EntityType
1     66              1     Product

Pictures表

Id  MimeType    SeoFilename  AltAttribute   TitleAttribute  
1   image/png   seoFilename1 altAttribute1  titleAttribute1 
2   image/png       seox         altx               titlex

我想写一个查询来打印Products 的列表，并根据imagesize 输入生成PictureUrl 列

伪代码：

@imageSizes={100,200}
foreach(imagesize in @imageSizes)
    select *,PictureUrl from products where Id=@id  

图片大小不是任何表格的一列，它只是用来生成url

预期结果：

Id   PictureUrl
10  http://localhost/content/images/thumbs/1_seoFilename1_100.png
11  http://localhost/content/images/thumbs/1_seoFilename1_200.png

更新

在1_seoFilename1_200.png中，1是图片ID，100和200是根据where子句生成的。如果我们只有 where imagesize=100 ，预期的结果将是

Id   PictureUrl
10  http://localhost/content/images/thumbs/1_seoFilename1_100.png

而@id 在EntityPictures 表中是EntityId。

Answer 1

这是您的查询。

要从image/png 中提取png，使用这个

substring(pt.MimeType, charindex('/', pt.MimeType, 1) + 1, 
        len(pt.MimeType) - 1)

完整查询（针对单个参数）

select ep.Id,
    concat('http://localhost/content/images/thumbs/'
      , ep.Id, '_', pt.SeoFilename, '_', @imgSize, '.', 
      substring(pt.MimeType, charindex('/', pt.MimeType, 1) + 1, 
        len(pt.MimeType) - 1)
    ) as PictureURL
from EntityPictures ep 
join Pictures pt on pt.Id= ep.EntityId
where ep.Id=@id 

要生成 N 行，您可以使用 CTE。

    with MultiRows (RowNum, ImageSize) as (      
       select 1 as RowNum, 100 AS ImageSize
       union all          
       select a.RowNum + 1, a.ImageSize + 100 AS ImageSize
       from   MultiRows a
       where  a.RowNum < 2
    )
    select t1.Id,  
            concat('http://localhost/content/images/thumbs/'
              , t1.Id, '_', t1.SeoFilename, '_', m.ImageSize, '.', 
              substring(t1.MimeType, charindex('/', t1.MimeType, 1) + 1, 
                len(t1.MimeType) - 1)
            ) as PictureURL 
    from  MultiRows m
    left join (
                select row_number() over (order by ep.id) as rn, ep.Id, pt.SeoFilename, pt.MimeType
                    from EntityPictures ep 
                join Pictures pt on pt.Id= ep.EntityId
                where ep.Id=@id 
            ) t1 on m.ROwNum = t1.rn;
    go

Answer 2

样品日期：

    SET QUOTED_IDENTIFIER ON
    GO
    CREATE TABLE [dbo].[Products](
        [Id] [int] NULL,
        [Name] [nvarchar](50) NULL
    ) ON [PRIMARY]
    GO
    SET ANSI_NULLS ON
    GO
    SET QUOTED_IDENTIFIER ON
    GO
    CREATE TABLE [dbo].[EntityPictures](
        [Id] [int] IDENTITY(1,1) NOT NULL,
        [EntityId] [int] NOT NULL,
        [PictureId] [int] NOT NULL,
        [DisplayOrder] [int] NOT NULL,
        [IsDefault] [bit] NOT NULL,
        [EntityType] [nvarchar](max) NULL,
     CONSTRAINT [PK_EntityPictures] PRIMARY KEY CLUSTERED 
    (
        [Id] ASC
    )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
    ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
    GO
    SET QUOTED_IDENTIFIER ON
    GO
    CREATE TABLE [dbo].[Pictures](
        [Id] [int] IDENTITY(1,1) NOT NULL,
        [PictureBinary] [varbinary](max) NULL,
        [MimeType] [nvarchar](max) NULL,
        [SeoFilename] [nvarchar](max) NULL,
        [AltAttribute] [nvarchar](max) NULL,
        [TitleAttribute] [nvarchar](max) NULL,
        [IsNew] [bit] NOT NULL,
     CONSTRAINT [PK_Pictures] PRIMARY KEY CLUSTERED 
    (
        [Id] ASC
    )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
    ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
    GO
    INSERT [dbo].[Products] ([Id], [Name]) VALUES (66, N'P1')
    INSERT [dbo].[Products] ([Id], [Name]) VALUES (67, N'P2')
    SET IDENTITY_INSERT [dbo].[EntityPictures] ON 

    INSERT [dbo].[EntityPictures] ([Id], [EntityId], [PictureId], [DisplayOrder], [IsDefault], [EntityType]) VALUES (1, 66, 1, 0, 0, N'Product')
    SET IDENTITY_INSERT [dbo].[EntityPictures] OFF
    SET IDENTITY_INSERT [dbo].[Pictures] ON 

    INSERT [dbo].[Pictures] ([Id], [PictureBinary], [MimeType], [SeoFilename], [AltAttribute], [TitleAttribute], [IsNew]) VALUES (1, 0x, N'image/png', N'seoFilename1', N'altAttribute1', N'titleAttribute1', 0)
    INSERT [dbo].[Pictures] ([Id], [PictureBinary], [MimeType], [SeoFilename], [AltAttribute], [TitleAttribute], [IsNew]) VALUES (2, 0x, N'image/png', N'seoFilenameoo', N'altAttributeoo', N'titleAttributeoo', 0)
    SET IDENTITY_INSERT [dbo].[Pictures] OFF

我的解决方案基于metal 解决方案：

declare @listOfIDs table (id int);
insert @listOfIDs(id) values(100),(200);    
declare @id int=66;
declare @baseUrl varchar(256)='http://localhost/content/images/thumbs/';

    select id,name,PictureURL from (select * from products p
    join (select ep.EntityId,
        concat(@baseUrl
          , ep.Id, '_', pt.SeoFilename, '_', l.id, '.', 
          substring(pt.MimeType, charindex('/', pt.MimeType, 1) + 1, 
            len(pt.MimeType) - 1)
        ) as PictureURL
    from dbo.EntityPictures ep 
    join dbo.Pictures pt on pt.Id= ep.PictureId
    right join @listOfIDs l on l.id=l.id 
    ) t on 1=1) x
    where x.Id=@id

Answer 3

首先，我假设您的图片表有一个指定“图像大小”的列？

如果是这样，请尝试以下方法：

SELECT ('http://localhost/content/images/thumbs/66_'+seoFilename1+'_'+imagesize+'.png') AS PictureUrl FROM Pictures WHERE Id = @id AND (imagesize = 100 or imagesize = 200)

还请注意，“localhost”一旦投入生产就必须更改。