.net - 简单的SQL到Linq查询，具有分组和汇总功能

我正在尝试使用linq来学习语法，但我不知道如何执行以下简单查询

SELECT DISTINCT
    user.firstname,
    user.lastname,
    COUNT(invoice.amount),
    SUM(invoice.amount)
FROM
    company_user
    INNER JOIN
        user
    ON
        company_user.user_id = user.user_id
    INNER JOIN
        invoice
    ON
        invoice.user_id= invoice.user_id
WHERE
    company_user.company_id = 1
GROUP BY
    user.firstname,
    user.lastname,
GO

将其转换为linq的任何帮助都会很棒。

最佳答案

您要查询的内容应与此非常接近:

var query =
    from cu in company_user
    where cu.company_id == 1
    join u in user on cu.user_id equals u.user_id
    join i in invoice on u.user_id equals i.user_id
    group i.amount by new
    {
        u.firstname,
        u.lastname,
    } into gs
    select new
    {
        firstname = gs.Key.firstname,
        lastname = gs.Key.lastname,
        count = gs.Count(),
        sum = gs.Sum(),
    };

享受!

关于.net - 简单的SQL到Linq查询，具有分组和汇总功能，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/3955986/