使用LINQ查询获取计数和不同项目？
|
我们有下面的SQL表：
Tag
----------------------------------------
ID | tagName | UserID
----------------------------------------
01 | c++ | 03
02 | c# | 03
03 | asp.net | 04
04 | programming | 05
05 | vb | 07
06 | php | 07
07 | java | 12
08 | class | 12
TagRelation
----------------------------------------
ID | tagID | topicID
----------------------------------------
01 | 01 | 22
02 | 02 | 22
03 | 08 | 22
04 | 06 | 12
05 | 02 | 12
06 | 04 | 104
07 | 02 | 104
08 | 01 | 104
09 | 02 | 17
10 | 05 | 17
TagRelation
DataClassesDataContext dbc = new DataClassesDataContext();
var query = from q in dbc.Tags
where q.UserID == this.UserID
from c in dbc.TagRelations
where c.tagID == q.id
select new
{
tagName = q.name.Distinct(),
repeatNumber = c.Count()
};
result (if UserID==3)
-------------------------
tagName | repeatNumber
-------------------------
c++ | 02
c# | 01
没有找到相关结果
已邀请:
2 个回复
豹芜澈
var q = ... group r by r.TagName into g; select new { TagName = g.Key, Count = g.Count() }; foreach (var i in q) { string tagName = i.TagName; int count = i.Count; }贡炮逗握惫
from t in dbc.Tags where t.UserID == this.UserID join r in dbc.TagRelations on t.id equals r.tagID group r by t into g select new { tagName = g.Key.name, repeatNumber = g.Count() };