Pat*_*ick 15 c# linq sql-server asp.net-mvc entity-framework
我需要根据汽车关键字搜索返回一个独特的记录列表,如:"Alfa 147"
问题是,因为我有3辆"阿尔法"汽车,它会返回1 + 3条记录(阿尔法和147结果似乎为1,阿尔法结果为3)
编辑:
SQL-Server查询看起来像这样:
SELECT DISTINCT c.Id, c.Name /*, COUNT(Number of Ads in the KeywordAdCategories table with those 2 keywords) */
FROM Categories AS c
INNER JOIN KeywordAdCategories AS kac ON kac.Category_Id = c.Id
INNER JOIN KeywordAdCategories AS kac1 ON kac.Ad_Id = kac1.Ad_Id AND kac1.Keyword_Id = (SELECT Id FROM Keywords WHERE Name = 'ALFA')
INNER JOIN KeywordAdCategories AS kac2 ON kac1.Ad_Id = kac2.Ad_Id AND kac2.Keyword_Id = (SELECT Id FROM Keywords WHERE Name = '147')
我的LINQ查询是:
var query = from k in keywordQuery where splitKeywords.Contains(k.Name)
join kac in keywordAdCategoryQuery on k.Id equals kac.Keyword_Id
join c in categoryQuery on kac.Category_Id equals c.Id
join a in adQuery on kac.Ad_Id equals a.Id
select new CategoryListByKeywordsDetailDto
{
Id = c.Id,
Name = c.Name,
SearchCount = keywordAdCategoryQuery.Where(s => s.Category_Id == c.Id).Where(s => s.Keyword_Id == k.Id).Distinct().Count(),
ListController = c.ListController,
ListAction = c.ListAction
};
var searchResults = new CategoryListByBeywordsListDto();
searchResults.CategoryListByKeywordsDetails = query.Distinct().ToList();
实体是:
public class Keyword
{
// Primary properties
public int Id { get; set; }
public string Name { get; set; }
}
// Keyword Sample Data:
// 1356 ALFA
// 1357 ROMEO
// 1358 145
// 1373 147
public class Category
{
// Primary properties
public int Id { get; set; }
public string Name { get; set; }
}
// Category Sample Data
// 1 NULL 1 Carros
// 2 NULL 1 Motos
// 3 NULL 2 Oficinas
// 4 NULL 2 Stands
// 5 NULL 1 Comerciais
// 8 NULL 1 Barcos
// 9 NULL 1 Máquinas
// 10 NULL 1 Caravanas e Autocaravanas
// 11 NULL 1 Peças e Acessórios
// 12 1 1 Citadino
// 13 1 1 Utilitário
// 14 1 1 Monovolume
public class KeywordAdCategory
{
[Key]
[Column("Keyword_Id", Order = 0)]
public int Keyword_Id { get; set; }
[Key]
[Column("Ad_Id", Order = 1)]
public int Ad_Id { get; set; }
[Key]
[Column("Category_Id", Order = 2)]
public int Category_Id { get; set; }
}
// KeywordAdCategory Sample Data
// 1356 1017 1
// 1356 1018 1
// 1356 1019 1
// 1357 1017 1
// 1357 1018 1
// 1357 1019 1
// 1358 1017 1
// 1373 1019 1
public class Ad
{
// Primary properties
public int Id { get; set; }
public string Title { get; set; }
public string TitleStandard { get; set; }
public string Version { get; set; }
public int Year { get; set; }
public decimal Price { get; set; }
// Navigation properties
public Member Member { get; set; }
public Category Category { get; set; }
public IList<Feature> Features { get; set; }
public IList<Picture> Pictures { get; set; }
public IList<Operation> Operations { get; set; }
}
public class AdCar : Ad
{
public int Kms { get; set; }
public Make Make { get; set; }
public Model Model { get; set; }
public Fuel Fuel { get; set; }
public Color Color { get; set; }
}
// AdCar Sample Data
// 1017 Alfa Romeo 145 1.6TDI 2013 ALFA ROMEO 145 1.6TDI 2013 12 2 1.6TDI 1000 1 2013 1 20000,0000 2052 AdCar
// 1018 Alfa Romeo 146 1.6TDI 2013 ALFA ROMEO 146 1.6TDI 2013 12 2 5 1.6TDI 1000 2 2013 1 20000,0000 2052 AdCar
// 1019 Alfa Romeo 147 1.6TDI 2013 ALFA ROMEO 147 1.6TDI 2013 12 2 6 1.6TDI 1000 3 2013 1 20000,0000 2052 AdCar
我期望搜索"ALFA"的结果是"汽车:3",搜索"ALFA 147"的结果是"汽车:1",实际上我得到的结果是"汽车:1 \n汽车:3"
小智 6
kac没有过滤单词...所以kac,kac1和kac2的这个连接将返回3行,因为这是此广告的关键字数量
你应该删除它..
试试这个:
SELECT DISTINCT
c.Id, c.Name /*, COUNT(Number of Ads in the KeywordAdCategories table with those 2 keywords) */
FROM
Categories AS c
INNER JOIN
KeywordAdCategories AS kac1 ON kac1.Keyword_Id = (SELECT Id
FROM Keywords
WHERE Name = 'ALFA')
AND kac1.Category_Id = c.Id
INNER JOIN
KeywordAdCategories AS kac2 ON kac1.Ad_Id = kac2.Ad_Id
AND kac2.Keyword_Id = (SELECT Id
FROM Keywords
WHERE Name = '147')
AND kac2.Category_Id = c.Id
我做了一个测试......
将环境设置为
declare @Keywords table(id int,name varchar(max))
insert into @Keywords(id,name)
values (1356,'ALFA')
,(1357,'ROMEO')
,(1358,'145')
,(1373,'147')
declare @Categories table(id int, name varchar(max))
insert into @Categories(id,name)
values (1,'Carros')
,(2,'Motos')
declare @KeywordAdCategories table(Keyword_Id int, ad_Id int,Category_Id int)
insert into @KeywordAdCategories (Keyword_Id , ad_Id,Category_Id)
values (1356, 1017,1)
,(1356, 1018,1)
,(1356, 1019,1)
,(1357, 1017,1)
,(1357, 1018,1)
,(1357, 1019,1)
,(1358, 1017,1)
,(1373, 1019,1)
我运行这两个查询:
--query 1
SELECT
c.Id, c.Name,COUNT(*) as [count]
FROM
@Categories AS c
INNER JOIN
@KeywordAdCategories AS kac1 ON kac1.Keyword_Id = (SELECT Id
FROM @Keywords
WHERE Name = 'ALFA')
AND kac1.Category_Id = c.Id
GROUP BY
c.Id, c.Name
我得到这个结果集:
Id Name count
----------- ---------- -----------
1 Carros 3
和两个单词的第二个查询......
--query 2
SELECT
c.Id, c.Name,COUNT(*) as [count]
FROM
@Categories AS c
INNER JOIN
@KeywordAdCategories AS kac1 ON kac1.Keyword_Id = (SELECT Id
FROM @Keywords
WHERE Name = 'ALFA')
AND kac1.Category_Id = c.Id
INNER JOIN
@KeywordAdCategories AS kac2 ON kac1.Ad_Id = kac2.Ad_Id
AND kac2.Keyword_Id = (SELECT Id
FROM @Keywords
WHERE Name = '147')
AND kac2.Category_Id = c.Id
GROUP BY
c.Id, c.Name
结果集是:
Id Name count
----------- ---------- -----------
1 Carros 1
这是你想要的吗？
噗，这真是脑残啊。我将查询分成几个部分，但它最后作为一个整体执行（var 结果）。我返回了匿名类，但意图很明确。
这是解决方案：
var keywordIds = from k in keywordQuery
where splitKeywords.Contains(k.Name)
select k.Id;
var matchingKac = from kac in keywordAdCategories
where keywordIds.Contains(kac.Keyword_Id)
select kac;
var addIDs = from kac in matchingKac
group kac by kac.Ad_Id into d
where d.Count() == splitKeywords.Length
select d.Key;
var groupedKac = from kac in keywordAdCategoryQuery
where addIDs.Contains(kac.Ad_Id)
group kac by new { kac.Category_Id, kac.Ad_Id };
var result = from grp in groupedKac
group grp by grp.Key.Category_Id into final
join c in categoryQuery on final.Key equals c.Id
select new
{
Id = final.Key,
Name = c.Name,
SearchCount = final.Count()
};
// here goes result.ToList() or similar