linq to entity DistinctBy && DefaultIfEmpty

it2022-06-27  83

根据某属性去重

使用第三方库:https://github.com/morelinq/MoreLINQ

Install-Package morelinq -Version 3.0.0 data.DistinctBy(x=>x.Id)

实现left join

使用DefaultIfEmpty(),是left join 没有DefaultIfEmpty(),是inner join

var query2 = ( from users in Repo.T_Benutzer from mappings in Repo.T_Benutzer_Benutzergruppen .Where(mapping => mapping.BEBG_BE == users.BE_ID).DefaultIfEmpty() from groups in Repo.T_Benutzergruppen .Where(gruppe => gruppe.ID == mappings.BEBG_BG).DefaultIfEmpty() select new { UserId = users.BE_ID ,UserName = users.BE_User ,UserGroupId = mappings.BEBG_BG ,GroupName = groups.Name } );

参考资料

https://stackoverflow.com/questions/19356439/left-join-in-linq-to-entities

转载于:https://www.cnblogs.com/Lulus/p/9556522.html

相关资源:数据结构—成绩单生成器

最新回复(0)