1、查询语句如下
SELECT UserID,MAX(CreatedTime) CreatedTime
FROM T_UserHistory
WHERE UserID IN ('123456')
GROUP BY UserID
2、转lambda后
var userIDs = new[] {'123456'};
var result = UserHis
.Where(u=> userIDs.Contains(u.UserID))
.GroupBy(x => x.UserID)
.Select(ug =>
new
{
UserID = ug.Key,
CreatedTime = ug.Max(x => x.CreatedTime)
});