A quoi ressemble tes tables?
celle des categories ,celle des photos et la porteuse entre les deux?
sinon par exemple:
Soit la table categories:
CREATE TABLE [dbo].[Categories](
[CatId] [int] IDENTITY(1,1) NOT NULL,
[CatLibelle] [nvarchar](100) NULL,
CONSTRAINT [PK_Categories] PRIMARY KEY CLUSTERED
(
[CatId] ASC
)WITH (PAD_INDEX OFF, STATISTICS_NORECOMPUTE OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
la table Images:
CREATE TABLE [dbo].[Images](
[imgId] [int] IDENTITY(1,1) NOT NULL,
[imgPath] [nvarchar](1000) NULL,
CONSTRAINT [PK_Images] PRIMARY KEY CLUSTERED
(
[imgId] ASC
)WITH (PAD_INDEX OFF, STATISTICS_NORECOMPUTE OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
et la porteuse:
CREATE TABLE [dbo].[CategoriesImages](
[catImgCatId] [int] NULL,
[catImgImgId] [int] NULL
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[CategoriesImages] WITH CHECK ADD CONSTRAINT [FK_CategoriesImages_Categories] FOREIGN KEY([catImgCatId])
REFERENCES [dbo].[Categories] ([CatId])
GO
ALTER TABLE [dbo].[CategoriesImages] CHECK CONSTRAINT [FK_CategoriesImages_Categories]
GO
ALTER TABLE [dbo].[CategoriesImages] WITH CHECK ADD CONSTRAINT [FK_CategoriesImages_Images] FOREIGN KEY([catImgImgId])
REFERENCES [dbo].[Images] ([imgId])
GOALTER TABLE [dbo].[CategoriesImages] CHECK CONSTRAINT [FK_CategoriesImages_Images]
GO
Le script te permettant de faire ce que tu veux est le suivant:
declare @CatId int
set @CatId=1--Id de ta categorie selectionnée
/**/
select I.imgId, I.imgPath
from dbo.Images I
INNER JOIN CategoriesImages CI ON CI.catImgImgId=I.imgId
where CI.catImgCatId=@CatId
J'espere que ca t'auras aidé .