Fluent NHibernate-从底部查询层次结构数据
本文关键字:层次结构 数据 查询 底部 NHibernate- Fluent | 更新日期: 2023-09-27 18:25:28
例如,如果我有一个类似的表
id | parent_id
-----------------
1 | null
2 | 1
3 | 1
4 | 1
5 | 2
6 | 3
7 | 3
8 | 4
9 | 7
....
层次结构树如下所示:
X1
|
------------------------------------------------------
| | |
X2 X3 X4
| | |
| ------------------ |
| | | |
X5 X6 X7 X8
|
X9
那么,我是否可以使用QueryOver
或Criteria
查询,当我输入id
时,它将返回从其父对象到顶部的所有parent_id
(或父对象)的列表?例如:
input | result
-----------------------
1 | null
2 | [1]
3 | [1]
5 | [2, 1]
8 | [4, 1]
9 | [7, 3, 1]
....
===============
工作查询(但必须调用数据库两次)
var roleIds = session.CreateSQLQuery("SELECT Id FROM dbo.fn_get_parent_roles(:id)")
.SetInt32("id", roleId)
.List<int>();
Role x = null;
var query = session.QueryOver<Role>(() => x)
.Where(Restrictions.In("x.RoleId", roleIds.ToArray()));
===============
更新:
var hierarchyQuery = new SQLCriterion(
new SqlString("{alias}.RoleId IN (SELECT Id FROM dbo.fn_get_parent_roles(:id))"),
new object[] { roleId },
new IType[] { NHibernateUtil.Int32 });
var results = session.QueryOver<Role>()
.Where(hierarchyQuery)
.List();
然后我收到了这样的消息:
Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
这是完整的StackTrace
at System.ThrowHelper.ThrowArgumentOutOfRangeException()
at System.Collections.Generic.List`1.get_Item(Int32 index)
at NHibernate.Criterion.SQLCriterion.ToSqlString(ICriteria criteria, ICriteriaQuery criteriaQuery, IDictionary`2 enabledFilters)
at NHibernate.Loader.Criteria.CriteriaQueryTranslator.GetWhereCondition(IDictionary`2 enabledFilters)
at NHibernate.Loader.Criteria.CriteriaJoinWalker..ctor(IOuterJoinLoadable persister, CriteriaQueryTranslator translator, ISessionFactoryImplementor factory, ICriteria criteria, String rootEntityName, IDictionary`2 enabledFilters)
at NHibernate.Loader.Criteria.CriteriaLoader..ctor(IOuterJoinLoadable persister, ISessionFactoryImplementor factory, CriteriaImpl rootCriteria, String rootEntityName, IDictionary`2 enabledFilters)
at NHibernate.Impl.SessionImpl.List(CriteriaImpl criteria, IList results)
at NHibernate.Impl.CriteriaImpl.List(IList results)
at NHibernate.Impl.CriteriaImpl.List[T]()
at NHibernate.Criterion.QueryOver`1.List()
at NHibernate.Criterion.QueryOver`1.NHibernate.IQueryOver<TRoot>.List()
at At2ClaimBO.Src.Repositories.UserRepo.GetUsers(String searchStr, Int32 roleId, Int32 page) in D:'Arunsawad'At2ClaimBO'At2ClaimBO'Src'Repositories'UserRepo.cs:line 85
at At2ClaimBO.Src.Services.ClaimService.GetUsers(String searchStr, Int32 roleLevel, Int32 page) in D:'Arunsawad'At2ClaimBO'At2ClaimBO'Src'Services'ClaimService.cs:line 1326
at At2ClaimBO.Controllers.AdminController.SearchHead(String search_str, String role_id, Int32 page) in D:'Arunsawad'At2ClaimBO'At2ClaimBO'Controllers'AdminController.cs:line 259
at lambda_method(Closure , ControllerBase , Object[] )
at System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters)
at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41()
at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49()
NHibernate本机不支持这一点-您必须使用类似于表值函数和SQL查询的东西:
假设您使用的是MSSQL服务器,以及支持表值函数的版本(可能是2008年以后的版本?):
SQL函数:
CREATE FUNCTION fnGetParents(@id INT)
RETURNS @tbl TABLE (ID INT NOT NULL)
AS
BEGIN
;WITH t AS (
SELECT ParentId AS Id
FROM Hierarchy
WHERE Id = @id
UNION ALL
SELECT ParentId
FROM Hierarchy
INNER JOIN t ON t.Id = Hierarchy.Id
)
INSERT INTO @tbl
SELECT DISTINCT Id FROM t
WHERE Id IS NOT NULL
RETURN;
END
然后得到结果:
session.CreateSQLQuery("SELECT Id FROM dbo.fnGetParents(:id)")
.SetInt32("id", id)
.List<int>();
如果你想把它包含在Criteria或QueryOver函数中,你可以使用SQLCriteria或者SQLProjection,例如:
var hierarchyQuery = new SQLCriterion(
new SqlString("{alias}.id IN (SELECT Id FROM dbo.fnGetParents(?))"),
new object[] {id},
new[] {NHibernateUtil.Int32});
var results = session.QueryOver<Hierarchy>()
.Where(hierarchyQuery)
.List();