过滤nHibernate中的连接

Question

我正在尝试构建一个nHibernate条件表达式来执行搜索.

给出以下数据模型:

• 操作可以具有零个或多个会话.
• 操作可以是零个以上的操作类型.

我想根据以下条件搜索所有会话:

• (必填)如果操作IsActive标志为true,则IsPublished标志为true

o(可选)以及操作状态/结束日期在用户指定的日期范围内

o(可选)以及会话regionid与用户指定的id匹配的位置

o(可选)以及会话分区与用户指定的id匹配的位置

o(可选)以及Operation.OperationTypes在用户指定的类型ID列表中

我会在sql中表达这个(给定所有可选参数已提供):

SELECT     
    [Session].*
FROM         
    [OperationTypeOperation] 
LEFT OUTER JOIN
    [Operation] ON [OperationTypeOperation].[OperationId] = [Operation].[OperationId]
RIGHT OUTER JOIN
    [Session] ON [Operation].[OperationId] = [Session].[OperationId]
WHERE
    ([Operation].[IsPublished] = 1) 
AND 
    ([Operation].[IsActive] = 1) 
AND 
    ([Session].[RegionId] = 66)
AND 
    ([Session].[DivisionId] = 99)
AND 
    ([Operation].[AdvertisingStartDate] < GETDATE()) 
AND 
    ([Operation].[AdvertisingEndDate] > GETDATE()) 
AND 
    ([OperationTypeOperation].[OperationTypeId] IN (1, 2, 3))

在我的nHibernate查询中:

public PagedResult<Session> Search(int? regionId, int? divisionId, DateTime? startDate, DateTime? endDate, IList<int> operationTypeId, int itemsPerPage, int page)
        {

            var criteria = _session.CreateCriteria(typeof(Session))
                .Add(Expression.Eq("IsActive", true))
                .Add(Expression.Eq("AcceptingApplications", true))
                .AddOrder(new Order("StartDate", false))
                ;

            if (regionId.HasValue)
                criteria.Add(Expression.Eq("Region.Id", regionId.Value));

            if (divisionId.HasValue)
                criteria.Add(Expression.Eq("Division.Id", divisionId.Value));

            if (startDate.HasValue)
                criteria.Add(Expression.Ge("StartDate", startDate.Value));

            if (endDate.HasValue)
                criteria.Add(Expression.Le("EndDate", endDate.Value));

            //Add the operation types
            if (operationTypeId.Count > 0)
            {
                var operationTypes = new Collection<OperationType>();
                foreach (int id in operationTypeId)
                {
                    operationTypes.Add(_session.Get<OperationType>(id));
                }
                //Join on the operations
                criteria.CreateCriteria("Operation")
                .Add(Expression.Eq("IsPublished", true))
                .Add(Expression.Eq("IsActive", true))
                .Add(Expression.Le("AdvertisingStartDate", DateTime.Now))
                .Add(Expression.Ge("AdvertisingEndDate", DateTime.Now))
                .CreateAlias("OperationTypes", "operationTypes", JoinType.InnerJoin)
                .Add(Expression.In("OperationTypes", operationTypes))
                .SetResultTransformer(new DistinctRootEntityResultTransformer())
                ;
            }
            else
            {
                //Join on the operations
                criteria.CreateCriteria("Operation")
                .Add(Expression.Eq("IsPublished", true))
                .Add(Expression.Eq("IsActive", true))
                .Add(Expression.Le("AdvertisingStartDate", DateTime.Now))
                .Add(Expression.Ge("AdvertisingEndDate", DateTime.Now))
                ;
            }

            return criteria.ToPagedResult<Session>(itemsPerPage, page);
        }

我的nHibernate函数抱怨操作类型并抛出异常"无法使用带有InExpression的集合".另外我不确定我是否正确过滤了连接的表格.任何人都可以权衡正确的方式将上述sql编写为nHibernate表达式吗？

Answer 1

我假设这OperationType是一个实体类(不是枚举).您不能使用In实体列表.您可以使用ID加入.

criteria
  .CreateCriteria("Operation")
  // add other expressions
  .CreateCriteria("OperationTypes", "operationTypes", JoinType.LeftOuterJoin)
  .Add(Expression.In("operationTypes.Id", operationTypeId))

我假设_session.Get(id)执行数据库查询.无论如何你应该避免这种情况.

PS:如果将OperationType映射为复合集合(带有<composite-element>标记),则遗憾的是,您无法将其与条件相连接.我不确定是否有解决方法.但有一个补丁待定.