我的任务是将一些旧的 SQL 存储过程转换为 LINQ 以进行我们正在进行的 EF 迁移,我有点难过。鉴于这是从现有应用程序的迁移,edmx 是首先生成数据库的。所以,我有一个我试图复制的 SQL 语句:
SELECT DISTINCT
d.DeliverySubscriptionId
, d.ContactId
, d.statementMacroId_fk
, m.Name as MacroName
, DeliveryMethod = REPLACE((SELECT DISTINCT
dm2.Name + ',' AS 'data()'
FROM
DeliverySubscription d2
JOIN
StatementMacro m2 on
d2.StatementMacroId_fk = m2.StatementMacroId
JOIN
DeliverySubscription_Method_Rel dmr2 ON
d2.DeliverySubscriptionId = dmr2.DeliverySubscriptionId_Fk
JOIN
dbo.DeliveryMethod dm2 ON
dmr2.DeliveryMethodId_Fk = dm2.DeliveryMethodId
WHERE
d.DeliveryConfigurationId_fk = @configurationId
AND
d.IsActive = 1
AND
D.DeliverySubscriptionId = D2.DeliverySubscriptionId FOR XML PATH('')) + '$', ',$', '')
FROM
DeliverySubscription d
INNER JOIN
StatementMacro m ON
d.StatementMacroId_fk = m.StatementMacroId
JOIN
DeliverySubscription_Method_Rel dmr ON
d.DeliverySubscriptionId = dmr.DeliverySubscriptionId_Fk
JOIN dbo.DeliveryMethod dm ON
dmr.DeliveryMethodId_Fk = dm.DeliveryMethodId
WHERE
d.DeliveryConfigurationId_fk = @configurationId
AND
d.IsActive = 1
特别是我遇到问题的部分是 JOIN ,它是一个关系表,表示和DeliverySubscription_Method_Rel
之间的多对多关系。DeliverySubscription
DeliveryMethod
这显示为:
[DeliverySubscription] * ---- * [Delivery Method]
在 edmx 的数据库图中。没有DeliverySubscription_Method_Rel
创建实体。正如您在 SQL 语句中看到的,JOIN 直接在关系表上,但我似乎无法弄清楚如何在 LINQ 中复制它。请帮忙!
更新:所以环顾网络,我发现了一个类似的例子,它建议做这样的事情:
from s in Context.DeliverySubscriptions
from dm in s.DeliveryMethods
join sm in Context.StatementMacroes on s.StatementMacroId_Fk equals sm.StatementMacroId
where s.DeliveryConfigurationId_Fk == configurationId
select new DeliverySubscription_dto
{
DeliverySubscriptionId = s.DeliverySubscriptionId,
QubeContactId = s.QubeContactId,
statementMacroId_fk = s.StatementMacroId_Fk,
MacroName = sm.Name,
DeliveryMethod = dm.Name.Replace("$","").Replace(",$","")
}
...但是,因为到目前为止我在应用程序中还有很多其他的事情要更改,所以我无法构建以进行测试,所以我只是想运行这个,让大家看看这是否正确。