首页 文章

C#Linq在多列上加入2个表,在GROUP上加入GROUP BY

提问于
浏览
1

我需要在五列上加入两个实体,我需要GROUP BY中的每一列GROUP BY在每个GROUP BY上获得一个COUNT . 虽然这对我来说是SQL的蛋糕,但我无可救药地混淆了我能为LINQ找到的每个例子 .

我发现以下两个问题(C# Linq Group By on multiple columns [duplicate]Group By Multiple Columns)与我的相似,但我仍然对如何做到这一点感到困惑 . 这是我的SQL语句:

SELECT  o.org_hq_name,
        o.org_command_name,
        o.org_region_name,
        o.org_installation_name,
        o.org_site_name,
        o.org_subsite_name,
        o.org_hq_id,
        o.org_command_id,
        o.org_region_id,
        o.org_installation_id,
        o.org_site_id,
        count(org_site_id) AS count

FROM    organization o, asset a

WHERE      o.org_hq_id = hq_org_id
AND        o.org_command_id = a.command_org_id
AND        o.org_region_id = a.region_org_id
AND        o.org_installation_id = a.installation_org_id
AND        o.org_site_id = a.site_org_id

GROUP BY o.org_hq_name,
        o.org_command_name,
        o.org_region_name,
        o.org_installation_name,
        o.org_site_name,
        o.org_subsite_name,
        o.org_hq_id,
        o.org_command_id,
        o.org_region_id,
        o.org_installation_id,
        o.org_site_id

我在下面加入:

var join1 =  from m in context.asset
             join o in context.organization
             on new {hqID = a.hq_org_id, commandID = a.command_org_id, regionID = a.region_org_id, installationID = a.installation_org_id, siteID = a.site_org_id}
             equals new {hqID = o.hq_id, commandID = o.command_id, regionID = o.region_id, installationID = o.installation_id, siteID = o.site_id}
             select new
             {
                 hqID = o.hq_id,
                 commandID = o.command_id,
                 regionID = o.region_id,
                 installationID = o.installation_id,
                 siteID = o.site_id
                 //hqId = o.count(org_site_id) AS count
             };

我有一个Group By下面:

var group1 = from a in context.asset
            group a by new
            {
                a.hq_org_id,
                a.command_org_id,
                a.region_org_id,
                a.installation_org_id,
                a.site_org_id

                // I am not sure how to get the count

            } into asset
            select new
            {
                // I cannot figure out how to join
            }

请帮助我在两个表上使用JOIN的GROUP BY语法,但是在两个表的MULTIPLE列上,并获取每个组的计数 .

1 回答

  • 3

    您的查询可以像Linc一样在Linq中重写

    var join1 =  from m in context.asset
             join o in context.organization
             on new {hqID = a.hq_org_id, commandID = a.command_org_id, regionID = a.region_org_id, installationID = a.installation_org_id, siteID = a.site_org_id}
             equals new {hqID = o.hq_id, commandID = o.command_id, regionID = o.region_id, installationID = o.installation_id, siteID = o.site_id}
             group new {m,o} by new {   o.org_hq_name,
                                        o.org_command_name,
                                        o.org_region_name,
                                        o.org_installation_name,
                                        o.org_site_name,
                                        o.org_subsite_name,
                                        o.org_hq_id,
                                        o.org_command_id,
                                        o.org_region_id,
                                        o.org_installation_id,
                                        o.org_site_id
                                    } into gr
             select new
             {
                org_hq_name = gr.Key.org_hq_name,
                org_command_name = gr.Key.org_command_name,
                org_region_name = gr.Key.org_region_name,
                org_installation_name = gr.Key.org_installation_name,
                org_site_name = gr.Key.org_site_name,
                org_subsite_name = gr.Key.org_subsite_name,
                org_hq_id = gr.Key.org_hq_id,
                org_command_id = gr.Key.org_command_id,
                org_region_id = gr.Key.org_region_id,
                org_installation_id = gr.Key.org_installation_id,
                org_site_id = gr.Key.org_site_id,
                Count = gr.Count()
             };
    

相关问题