sql-server-2008 - 加入 4 个表时如何调整值？

Question

tbl_category

pk_int_category_id,
vchr_category_name

tbl_projects

fk_int_category_id,
pk_int_project_id,
vchr_project_name,
vchr_project_description,
bln_project_status

tbl_project_album

pk_int_album_id
fk_int_project_id
vchr_album_name
vchr_album_description

tbl_picture

fk_int_album_id,
pk_int_picture_id,
vchr_picture_name,
vchr_picture_description,
vchr_picture_path

向表2个类别c1和c2插入数据，输入2或3个项目，对应每个类别。c1p1、c1p2、c2p1、c2p2 等。每个项目至少应有 2 个相册，每个相册至少应有 2 张图片

1. 创建一个包含以下内容的结果集：
   

   Pk_category_id,
   category_name,
   Pk_project_id,
   project_name,
   Pk_Picture_id,
   Picture_name,
   Pk_Album_id,
   Album_name
   

2. 过滤结果集以显示所有项目和所有相册以及与相册对应的一张图片

3. 过滤结果集，显示所有项目，并显示一个项目对应的一张图片和一张相册

Answer 1

select c.pk_int_category_id ,c.vchr_category_name,p.pk_int_project_id,p.vchr_project_name,pr.pk_int_picture_id,pr.vchr_picture_name,a.pk_int_album_id,a.vchr_album_name
from tbl_category c,tbl_projects p,tbl_project_album a, tbl_picture pr
where c.pk_int_category_id=p.fk_int_category_id and p.pk_int_project_id=a.fk_int_project_id and a.pk_int_album_id=pr.fk_int_album_id;

Answer 2

过滤结果集以显示所有项目和所有相册以及与相册对应的一张图片

` select p.vchr_project_name,a.vchr_album_name,pr.vchr_picture_name from tbl_projects p,tbl_project_album A,tbl_picture pr where p.pk_int_project_id=a.fk_int_project_id and a.pk_int_album_id=pr.fk_int_album_id group by a.vchr_album_name ;