Linq Join中的大于条件

使用LINQ连接不能做到这一点-LINQ只支持 等分

var query = from e in entity.M_Employee
            from p in entity.M_Position
            where e.PostionId >= p.PositionId
            select p;

或者是一种稍有不同但相当的方法:

var query = entity.M_Employee
                  .SelectMany(e => entity.M_Position
                                      .Where(p => e.PostionId >= p.PositionId));

from e in entity.M_Employee
from p in entity.M_Position.Where(p => e.PostionId >= p.PositionId)
select p;

将生成完全相同的SQL (INNER JOIN Position P ON E..PostionId >= P.PositionId).

var currentDetails = from c in customers
                  group c by new { c.Name, c.Authed } into g
                  where g.Key.Authed == "True"
                  select g.OrderByDescending(t => t.EffectiveDate).First();

var currentAndUnauthorised = (from c in customers
                           join cd in currentDetails
                           on c.Name equals cd.Name
                           where c.EffectiveDate >= cd.EffectiveDate
                           select c).OrderBy(o => o.CoverId).ThenBy(o => o.EffectiveDate);

如果您有一个历史细节变更表,包括授权状态和生效日期。第一个查询查找每个客户的当前详细信息,第二个查询添加表中所有后续未经授权的详细信息更改。