c# - 如何使用左连接、聚合和 where 子句创建 Linq to Sql

Question

有谁知道如何将此查询转换为 LINQ to SQL？

SELECT posts.*, count(COMMENTS.*) AS comment_count FROM POSTS
LEFT JOIN COMMENTS on POSTS.id = COMMENTS.post_id
WHERE comments.date IS NULL OR comments.date >= [NOW]
GROUP BY posts.id
ORDER BY comment_count DESC

它在 SQL 中很简单，但是我无法将 linq 转为 sql。任何帮助，将不胜感激！

谢谢

Answer 1

你想要这样的东西：

var query =
    from p in POSTS
    join c in COMMENTS on p.id equals c.post_id into cs
    group new
    {
        Post = p,
        Comments = cs
            .Where(c1 => c1.date >= DateTime.Now)
            .Count(),
    } by p.id;

Answer 2

只是一个建议，您可以随时使用这个很棒的工具

http://www.sqltolinq.com/

帮助转换