如何在 NHibernate 条件查询中使用 DatePart [英] How to use DatePart in an NHibernate Criteria Query

问题描述

在我的网站上，人们可以购买车辆零件.我想为客户创建一份报告，以查看他们每月在网站上花费的零件数量，并允许他们按日期进行过滤.如果我用 SQL 编写它，我会这样写:

On my site, people can buy parts for vehicles. I want to create a report for a customer to see how much they have spent on parts per month on the site, and allow them to filter by date. If I was writing it in SQL, I would write this:

SELECT
    v.id,
    DATEPART(YEAR, o.order_date), 
    DATEPART(MONTH, o.order_date),
    SUM(i.unit_price * i.quantity)
FROM vehicles v
    join order_items i on v.id = i.truck_id
    join orders o on o.order_id = i.order_id
WHERE v.customer_id = @CustomerId
    AND o.order_date > @StartDate
    AND o.order_date < @EndDate
GROUP BY DATEPART(YEAR, o.order_date), DATEPART(MONTH, o.order_date)

这个查询是否可以作为 NHibernate 中的 Criteria 查询?

Is this query even possible as a Criteria query in NHibernate?

推荐答案

有办法:

CurrentSession.CreateCriteria(typeof(Object)).Add(Expression.Eq(Projections.SqlFunction("day", NHibernateUtil.DateTime, Projections.Property("DateTimeProperty")), pvDay))

其中day"是您希望从日期(DateTimeProperty")中获得的值，而 pvDay 是您要与之进行比较的日期.

Where "day" is the value you'd like to get from the date ("DateTimeProperty") and pvDay is the day you're comparing it to.

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