如何为 linq2db 创建 ClickHouse countIf 函数的表达式？

Question

如何将 clickhouse countIf 函数迁移到 linq2db？

例子：

来自 =>

SELECT customer_id,
   countIf(customer_id, active_month between 0 and 1) as active_month1
FROM myt_table
GROUP BY customer_id

到=>

from x in my_table
group x by x.customerId into g
select new {
    CustomerId = g.Key,
    ActiveMonth1 = Sql.CountIf(x, p => p.customerId, p => p.ActiveMonth.between(1, 6)) 
}

我试过这个选项，但它有问题

from x in MyTable
group x by x.CustomerId into g
select new {
    CustomerId = g.Key,
    FirstMonthCount = g.Count(p => 1 >= p.ActiveMonth && p.ActiveMonth <= 6)
}

Answer 1

有什么理由不能用active_month 上的 WHERE 子句重写它并使用标准的count()？