C#Linq将两个表连接到多个列上,并按分组进行计数
我需要将五列上的两个实体连接起来,并且我需要按SELECT plus中的每列进行分组,并获得每个GROUP BY的计数。虽然这在SQL中对我来说是小菜一碟,但对于我能找到的每个LINQ示例,我都感到无可救药的困惑 我发现以下两个问题(和)与我的问题类似,但我仍然对如何做到这一点感到困惑。以下是我的SQL语句:C#Linq将两个表连接到多个列上,并按分组进行计数,linq,join,count,group-by,aggregate,Linq,Join,Count,Group By,Aggregate,我需要将五列上的两个实体连接起来,并且我需要按SELECT plus中的每列进行分组,并获得每个GROUP BY的计数。虽然这在SQL中对我来说是小菜一碟,但对于我能找到的每个LINQ示例,我都感到无可救药的困惑 我发现以下两个问题(和)与我的问题类似,但我仍然对如何做到这一点感到困惑。以下是我的SQL语句: SELECT o.org_hq_name, o.org_command_name, o.org_region_name, o.org_in
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
我在下面有一个链接:
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
};
我在下面有一个小组:
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
}
请帮助我了解在两个表上,但在两个表的多个列上使用联接进行分组的语法,并获取每个分组的计数。您的查询可以像这样在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()
};
嘿,崔佛!我有一个新问题,是这个问题的续集。也许这对你来说是个简单的问题。