Question

我是nHibernate和QueryOver的新手，并且无法在C＃中将一些sql重写为QueryOver。谁能帮我？我特别的问题是我通过包含具有连接值的IsLike的析取加入子查询，我找不到正确的方法。

以下是所涉及的数据库表的简化版本以及一些示例数据：

create table Rating (
  id          INT,
  description VARCHAR(20),
  value       INT
);

create table Category (
  id            INT,
  categoryName  VARCHAR(20),
  parentId      INT,
  path          VARCHAR(100)
);

create table Movie (
  id              INT,
  categoryId      INT,
  title           VARCHAR(50),
  description     VARCHAR(500),
  editorsRatingId INT,
  usersRatingId   INT
);

insert into Rating values (34, 'Bad', 1);
insert into Rating values (35, 'Good', 5); 
insert into Rating values (36, 'Excellent', 9);

insert into Category values (1, 'Sports', null, 'SPO');
insert into Category values (2, 'Baseball', 1, 'SPO/BAB');
insert into Category values (3, 'Motor', 1, 'SPO/MOT');
insert into Category values (4, 'Documentary', null, 'DOC');
insert into Category values (5, 'Nature', 4, 'DOC/NAT');
insert into Category values (6, 'Political', 4, 'DOC/POL');
insert into Category values (7, 'Constructions', 4, 'DOC/CON');

insert into Movie values (1, 3, 'A motor sports title', 'A motor sports description', 35, 34);
insert into Movie values (2, 2, 'A baseball title', 'A baseball description', 35, 36);
insert into Movie values (3, 5, 'A nature documentary', 'A nature documentary description', 36, 35);
insert into Movie values (4, 7, 'A construction documentary', 'A construction documentary description', 35, 36);

这是我想用QueryOver构建的sql：

--Try running this with 0, 1 and 4 as :parentId
select c1.id, c1.categoryName, max(subQuery.eRating) as eRating1, max(subQuery.uRating) as uRating1
from Category c1
  join (
    select c.path, max(editorsRating.value) as eRating, max(usersRating.value) as uRating
    from Category c
      join Movie m on (m.categoryId = c.id)
      join Rating editorsRating on (editorsRating.id = m.editorsRatingId)
      join Rating usersRating on (usersRating.id = m.usersRatingId)
    group by c.path
    ) as subQuery on (subQuery.path = c1.path or subQuery.path like concat(c1.path,'/%'))
where coalesce(c1.parentId, 0) = :parentId
group by c1.id, c1.categoryName

评级值应始终返回在所有级别的每个类别项的子类别中找到的汇总最大值。

如果有人能给我一个提示，我将不胜感激，特别是在子查询加入连接值的部分。

nhibernate QueryOver子查询连接在连接的IsLike上

0 个答案: