Question

我有使用EF 6.X的Web应用程序（ASP.NET MVC 5.X），我搜索和研究关于提高EF性能我使用这种方式来改进这一点。我有一个查询，它有11个连接到另一个表，当我用EF Profiler配置此查询得到以下结果：

查询持续时间： 25254 ms / 25254 ms
通知：
1. 嵌套选择语句太多。
2. 声明中的条款太多
3. 此声明包含太多关节，可能会影响性能

更多细节：我的SQL查询行数 2260 ，TSQL查询为here。

如何改进此查询并获得最佳性能？

public Task<UserProfileDto> GetUserForProfileAsync(long accountId, Guid userId)
    {
        return _users
            .AsNoTracking()
            .Where(user => user.AccountId == accountId)
            .Include(user => user.Certificates)
            .Include(user => user.WorkExperiences)
            .Include(user => user.ExchangeAccount)
            .Include(user => user.SocialNetwork)
            .Include(user => user.ActivityLogs)
            .Include(user => user.Certificates)
            .Include(user => user.Visitors)
            .Include(user => user.Crafts)
            .Include(user => user.Followings)
            .Include(user => user.Followers)
            .Include(user => user.Notifications)
            .Select(user => new UserProfileDto()
            {
                NotificationCount = user.Notifications.Count(notification => !notification.IsRead),
                FollowerCount = user.Followers.Count(following => following.FollowingId == user.Id),
                FollowingCount = user.Followings.Count,
                FollowedByCurrentUser = user.Followers.Any(following => following.FollowerId == userId),
                PostCount = user.Posts.Count,
                DisplayName = user.DisplayName,
                AccountId = user.AccountId,
                UserName = user.UserName,
                ImageName = user.ImageName,
                AvatarUrl = user.AvatarUrl,
                LastSeen = user.LastSeen,
                VisitorCount = user.Visitors.Count,
                AboutMe = user.AboutMe,
                IsAdmin = user.IsSystemAccount,
                LastSeenMode = user.LastSeenMode,
                IsSystemAccount = user.IsSystemAccount,
                IsVerifiedAccount = user.IsVerifiedAccount,
                WebSiteUrl = user.WebSiteUrl,
                LastPosts =
                    user.Posts.Where(post => !post.IsDeleted)
                        .OrderByDescending(post => post.CreatedDate)
                        .Select(post => new UserLastPostDto()
                        {
                            Id = post.Id,
                            Title = post.Title,
                            CreatedDate = post.CreatedDate
                        })
                        .Take(5).ToList(),

                LastActivityLogs =
                    user.ActivityLogs
                        .OrderByDescending(log => log.OperatedOn)
                        .Select(l => new UserLastActivity()
                        {
                            Description = l.Description
                        })
                        .Take(5).ToList(),
                Certificates = user.Certificates,
                Craft = user.Crafts,
                ExchangeAccount = user.ExchangeAccount,
                SocialNetwork = user.SocialNetwork.Select(network => new NetDto()
                {
                    Icon = network.Icon,
                    UserName = network.UserName,
                    UserNameFormat = network.UserNameFormat
                }).ToList(),
                WorkExperiences = user.WorkExperiences,
            })
            .SingleOrDefaultAsync();
    }

改善实体框架查询性能

0 个答案: