Question

我有一个与自身具有ManyToMany关系的表。因此，我的H2-Database中有两个表：

supporting_asset:           supporting_asset_dependencies:
id | provided_csc           dependencies_id | supporting_assets_id 
------------------          ---------------------------------------
1  |  A1                           1        |          2
2  |  A3                           1        |          3
3  |  A2

我有一个计算出的属性“ minCSC”，要计算它，我使用了@Formula批注：

@Formula(value="(Select min(sa.provided_csc) from supporting_asset_dependencies sad right join supporting_asset sa on sa.id = sad.dependencies_id where sad.supporting_assets_id = id group by id)")

这很好用，但是依赖的资产可以拥有它们自己的依赖项。有了这个，我得到了一个多层次的依赖树。我的目标是从此树中获取最小的csc。

我尝试过：

WITH RECURSIVE tree(id, provided_csc, dep_id) 
AS (SELECT sa.id, sa.provided_csc, sad.supporting_assets_id 
        FROM supporting_asset_dependencies AS sad 
            JOIN supporting_asset AS sa 
                ON sa.id=sad.dependencies_id 
        WHERE sad.supporting_assets_id=2 
    UNION ALL 
    SELECT child.id, child.provided_csc, childd.supporting_assets_id 
        FROM supporting_asset_dependencies AS childd 
            JOIN supporting_asset AS child 
                ON child.id=childd.dependencies_id 
    JOIN tree ON childd.supporting_assets_id=tree.id ) 
SELECT min(provided_csc) 
FROM tree

但是我收到“ SQL语句中的语法错误”。该公式似乎被计算为：

(SUPPORTING2_.WITH[*] TREE(SUPPORTING2_.ID, SUPPORTING2_.PROVIDED_CSC, SUPPORTING2_.DEP_ID) AS ( ..
.. ) SELECT MIN(SUPPORTING2_.PROVIDED_CSC) FROM TREE) AS FORMULA0_1_,

它似乎不知道“ with recursive”命令，并试图将其作为表的字段来查找。

我该如何更改查询才能使其正常工作，或者有另一种方法可以实现我想要的？

---更新--- 我稍微更改了查询，然后在DB Fiddle上将其用于SQLite数据库。它似乎也可以在h2网络控制台中工作。

带有匹配表的Hibernate @Formula递归查询

0 个答案: