使用左连接获取不适当的输出
Getting inappropriate output with left join
我正在尝试获取变体列表，并且对于每个变体都获取所有 subvariants list，而不管子变体适用于何处
特别是 Test say 100。这是示例数据：
Id TestId SourceSubVariantId TargetSubVariantId DiffPerc
114 100 66 67 100.00
115 100 67 68 100.00
116 100 70 71 99.99
我有 3 个变体 1 的子变体：
Id=66,Name=Abc
Id=68,Name=Pqr
Id=69,Name=xyz
我有 3 个变体 2 的子变体 :
Id=70,Name=lmn
Id=71,Name=xxx
Id=72,Name=hhh
但是请注意，在我的输出中，我正在为 Variant1 CustomSubvariantList:
中的 Variants 2 subvariants list 获取所有 Id as 0
数据模型：
public class Variants
{
public int Id { get; set; }
public string Name { get; set; }
public string Type { get; set; }
public virtual ICollection<SubVariants> SubVariants { get; set; }
}
public class SubVariants
{
public int Id { get; set; }
public int VariantId { get; set; }
public string Name { get; set; }
public virtual Variants Variants { get; set; }
public virtual ICollection<TestOperation> TestOperation { get; set; }
public virtual ICollection<TestOperation> TestOperation1 { get; set; }
}
public class TestOperation
{
public int Id { get; set; }
public Nullable<int> TestId { get; set; }
public int SourceSubVariantId { get; set; }
public int TargetSubVariantId { get; set; }
public decimal DiffPerc { get; set; }
public virtual SubVariants SubVariants { get; set; }
public virtual SubVariants SubVariants1 { get; set; }
public virtual Test Test { get; set; }
}
查询：
int testId=100;
var query =
from v in context.Variants
where v.Type == "Add"
select new
{
ParentVariant = v.Name,
Type = v.Method,
CustomSubvariantList =
(
from svName in context.SubVariants.Select(sv => sv.Name).Distinct()
join x in
(
from sv in v.SubVariants
from to in sv.TestOperation
where to.TestId == testId
orderby sv.Id
select new
{
sv.Name,
to.DiffPerc,
SourceId = (int?)to.SubVariants.Id,
TargetID=(int?)to.SubVariants1.Id
}
)
on svName equals x.Name into g
from x in g.DefaultIfEmpty()
orderby x.SourceId
select new
{
SourceId=x.SourceId ?? 0,
TargetId=x.TargetID ?? 0,
Name = svName,
DiffPerc = x.DiffPerc
}
).ToList()
};
更新： 根据评论，这是示例输入和预期输出：
案例 1:当所有父变体的子变体名称不同时
变体：
Id Name Type CategoryId
11 Variant1 Add 1
12 Variant2 Add 1
13 Variant3 Add 1
14 Variant4 Add 1
子变量：
Id VariantId Name
66 11 Abc
67 11 PQR
68 11 Xyz
70 12 lmn
71 12 xxx
72 12 hhh
试运行：
Id TestId SourceSubVariantId TargetSubVariantId DiffPerc
114 100 66 67 10.00
115 100 67 68 20.00
114 100 70 71 40.00
115 100 71 72 50.00
预期输出：
情况 2:当子变体名称在所有父变体中都相同时:
子变量：
Id VariantId Name
66 11 Abc
67 11 PQR
68 11 Xyz
70 12 Abc
71 12 PQR
72 12 Xyz
预期输出：
我们在聊天中进行了一些讨论，直到我明白了你想要什么。
这是代码：
class Program
{
static void Main(string[] args)
{
VariantsEntities db=new VariantsEntities();
var queryResult = db.Variants.AsEnumerable().Select(x => new PageViewModel
{
ParentVariant = x.Name,
Type = x.Type,
CustomSubvariantList = GetCustomSubVariants(x.Id,db).ToList()
}).ToList();
var jsonObj = JsonConvert.SerializeObject(queryResult);
Console.WriteLine(jsonObj);
Console.ReadKey();
}
private static IEnumerable<Customsubvariantlist> GetCustomSubVariants(int variantId, VariantsEntities db)
{
var subVariants = db.SubVariants.ToList();
foreach (var subVariant in subVariants)
{
var obj=new Customsubvariantlist();
obj.Name = subVariant.Name;
var testOpTarget = db.TestOperations
.FirstOrDefault(x => x.TargetSubVariantId == subVariant.Id);
var testOpSource = db.TestOperations
.FirstOrDefault(x => x.SourceSubVariantId == subVariant.Id);
if (subVariant.VariantId == variantId)
{
obj.Value = testOpTarget == null ?
testOpSource?.SourceValue : testOpTarget?.TargetValue;
obj.DiffPerc = testOpTarget?.DiffPerc;
}
else
{
obj.Value = null;
obj.DiffPerc = null;
}
yield return obj;
}
}
}
您只需要替换DbContext 名称，然后进行测试即可。
这是结果：
[
{
"ParentVariant": "Variant1",
"Type": "Add",
"CustomSubvariantList": [
{
"Name": "Abc",
"Value": 200,
"DiffPerc": null
},
{
"Name": "Pqr",
"Value": 300,
"DiffPerc": 100.0
},
{
"Name": "xyz",
"Value": 500,
"DiffPerc": 200.0
},
{
"Name": "lmn",
"Value": null,
"DiffPerc": null
},
{
"Name": "xxx",
"Value": null,
"DiffPerc": null
},
{
"Name": "hhh",
"Value": null,
"DiffPerc": null
}
]
},
{
"ParentVariant": "Variant2",
"Type": "Add",
"CustomSubvariantList": [
{
"Name": "Abc",
"Value": null,
"DiffPerc": null
},
{
"Name": "Pqr",
"Value": null,
"DiffPerc": null
},
{
"Name": "xyz",
"Value": null,
"DiffPerc": null
},
{
"Name": "lmn",
"Value": 1000,
"DiffPerc": null
},
{
"Name": "xxx",
"Value": 2000,
"DiffPerc": 1000.0
},
{
"Name": "hhh",
"Value": 4000,
"DiffPerc": 2000.0
}
]
}
]
您可以从 here 下载示例项目。这个项目是用你发给我的示例数据库完成的，数据库优先也是如此，一些道具或表格可能有不同的名称，请在你的项目中移动代码之前检查这一点。
基本上我做了什么：
创建了一个新的控制台应用程序项目
我从你的 json 对象中得到了模型（我复制了 json 对象并将其粘贴到 class 中，使用（vs 菜单）编辑 - > 过去特别 -> 过去 JSON 为 类。
因为你想要每个 Varian 的所有 SubVariants，我创建了一个单独的方法来处理你创建 CustomSubVariantList 的规则。在这种方法中，我迭代抛出所有 SubVariants 并根据您的条件创建对象。
更新： 您在一次查询中的解决方案：
static void Main(string[] args)
{
VariantsEntities db = new VariantsEntities();
var result = from x in db.Variants
select new PageViewModel
{
ParentVariant = x.Name,
Type = x.Type,
CustomSubvariantList = (from z in db.SubVariants
let testOpTarget=z.TestOperations1
.FirstOrDefault(q=>q.TargetSubVariantId==z.Id)
let testOpSource=z.TestOperations
.FirstOrDefault(q=>q.SourceSubVariantId==z.Id)
select new Customsubvariantlist
{
Name = z.Name,
Value = x.Id==z.VariantId?
testOpTarget.TargetValue??
testOpSource.SourceValue:null,
DiffPerc = x.Id==z.VariantId?
testOpTarget.DiffPerc:null
}).ToList()
};
var json = JsonConvert.SerializeObject(result.ToList());
Console.WriteLine(json);
Console.ReadKey();
}
此查询产生与上述方法相同的结果。
请让我知道您是否需要！！
更新：这是案例 2 的查询
var result = from x in db.Variants
select new PageViewModel
{
ParentVariant = x.Name,
Type = x.Type,
CustomSubvariantList = (from z in db.SubVariants.GroupBy(g => g.Name)
.Select(g => g.FirstOrDefault(d => d.VariantId == x.Id) ?? g.FirstOrDefault())
let testOpTarget = z.TestOperations1
.FirstOrDefault(q => q.TargetSubVariantId == z.Id)
let testOpSource = z.TestOperations
.FirstOrDefault(q => q.SourceSubVariantId == z.Id)
select new Customsubvariantlist
{
Name = z.Name,
SubVariantId = z.Id,
CombineName =(z.TestOperations.Any() || z.TestOperations1.Any())?
testOpTarget.TargetValue.HasValue?
testOpTarget.SubVariant.Name+" to "+testOpTarget.SubVariant1.Name : null: "Undefined",
Value = x.Id == z.VariantId
? testOpTarget.TargetValue ??
testOpSource.SourceValue
: null,
DiffPerc = x.Id == z.VariantId
? testOpTarget.DiffPerc
: null
}).OrderBy(k => k.SubVariantId).ToList()
};
这是您的查询的 "variant".. 它提取所有 SubVariants 每个 Variant(s) 的顺序，因为它们在 table SubVariants 中（通过它们的自动种子 Sql Server Identity Id)，不考虑涉及的 TestOperation 并避免重复作为您的预期输出。
不幸的是，不可能始终将所有子变量指定为源和目标子变量，因为此信息取决于测试操作，实际上测试操作决定子变量是 "source" 还是 "target"。因此，如果某些子变体未包含在测试操作 records/entity 中，则它们不能作为源或目标出现。解决方法可能是附加到返回的匿名类型 "Name" 属性 旁边，还有 "Id SubVar"
我添加了 2 个 DTO，因为 entity framework 不允许使用 distinct().ToList() 方法来保留顺序和应用自定义不同规则，所以我添加了一个步骤以从 Link 传递到Link 处的 EF 通过 dto 对象来对象，并以这种方式使应用不同的自定义规则成为可能..
public class CustomerVariantDTO
{
public String Type;
public String ParentVariant;
public IEnumerable<CustomerSubVariantDTO> CustomSubvariantList;
}
public class CustomerSubVariantDTO
{
public int? VariantId;
public int? SubVariantId;
public int? SourceId;
public int? TargetId;
public String Name;
public Decimal? DiffPerc;
}
sealed class CustomerSubVariantDTOComparer : IEqualityComparer<CustomerSubVariantDTO>
{
public int GetHashCode(CustomerSubVariantDTO obj)
{
return 0;
}
public bool Equals(CustomerSubVariantDTO x, CustomerSubVariantDTO y)
{
return x.SourceId == y.SourceId &&
x.TargetId == y.TargetId &&
x.Name == y.Name &&
x.DiffPerc == y.DiffPerc;
}
}
public void DoTestOfCustomerVariantDTO()
{
int testId = 1;
using (var context = new VariantsEntities())
{
var query =
(from v in context.Variants
where v.Type == "Add"
select new CustomerVariantDTO
{
ParentVariant = v.Name,
Type = v.Type,
CustomSubvariantList =
(
from sv in context.SubVariants.Select(sv => sv)
join x in
(
from svparent in v.SubVariants
from to in svparent.TestOperation
where to.TestId == testId
select new
{
svparent.Name,
to.DiffPerc,
SourceId = (int?)to.SubVariants.Id ?? 0,
TargetId = (int?)to.SubVariants1.Id ?? 0
}
)
on sv.Name equals x.Name into g
from x in g.DefaultIfEmpty()
select new CustomerSubVariantDTO{
VariantId = sv.VariantId,
SubVariantId = sv.Id,
SourceId = (int?)x.SourceId ?? sv.TestOperation.Select(to => to.SourceSubVariantId).FirstOrDefault(),
TargetId = (int?)x.TargetId ?? sv.TestOperation.Select(to => to.TargetSubVariantId).FirstOrDefault(),
Name = sv.Name,
DiffPerc = x.DiffPerc
}
).OrderBy(csv => new { csv.VariantId, csv.SubVariantId })
}).ToList();
var listCustomVariants =
query.Select(v => new{
Type = v.Type,
ParentVariant = v.ParentVariant,
CustomSubvariantList = v.CustomSubvariantList.Distinct(new CustomerSubVariantDTOComparer()).ToList()
});
foreach (var item in listCustomVariants){
Console.WriteLine($"Type: {item.Type} - ParentVariant: {item.ParentVariant} ");
foreach (var csubvar in item.CustomSubvariantList)
Console.WriteLine($"SourceId: {csubvar.SourceId} - TargetiId: {csubvar.TargetId} - NAme: {csubvar.Name} - DiffPerc: {csubvar.DiffPerc} ");
}
}
}
我正在尝试获取变体列表，并且对于每个变体都获取所有 subvariants list，而不管子变体适用于何处
特别是 Test say 100。这是示例数据：
Id TestId SourceSubVariantId TargetSubVariantId DiffPerc
114 100 66 67 100.00
115 100 67 68 100.00
116 100 70 71 99.99
我有 3 个变体 1 的子变体：
Id=66,Name=Abc
Id=68,Name=Pqr
Id=69,Name=xyz
我有 3 个变体 2 的子变体 :
Id=70,Name=lmn
Id=71,Name=xxx
Id=72,Name=hhh
但是请注意，在我的输出中，我正在为 Variant1 CustomSubvariantList:
Variants 2 subvariants list 获取所有 Id as 0
数据模型：
public class Variants
{
public int Id { get; set; }
public string Name { get; set; }
public string Type { get; set; }
public virtual ICollection<SubVariants> SubVariants { get; set; }
}
public class SubVariants
{
public int Id { get; set; }
public int VariantId { get; set; }
public string Name { get; set; }
public virtual Variants Variants { get; set; }
public virtual ICollection<TestOperation> TestOperation { get; set; }
public virtual ICollection<TestOperation> TestOperation1 { get; set; }
}
public class TestOperation
{
public int Id { get; set; }
public Nullable<int> TestId { get; set; }
public int SourceSubVariantId { get; set; }
public int TargetSubVariantId { get; set; }
public decimal DiffPerc { get; set; }
public virtual SubVariants SubVariants { get; set; }
public virtual SubVariants SubVariants1 { get; set; }
public virtual Test Test { get; set; }
}
查询：
int testId=100;
var query =
from v in context.Variants
where v.Type == "Add"
select new
{
ParentVariant = v.Name,
Type = v.Method,
CustomSubvariantList =
(
from svName in context.SubVariants.Select(sv => sv.Name).Distinct()
join x in
(
from sv in v.SubVariants
from to in sv.TestOperation
where to.TestId == testId
orderby sv.Id
select new
{
sv.Name,
to.DiffPerc,
SourceId = (int?)to.SubVariants.Id,
TargetID=(int?)to.SubVariants1.Id
}
)
on svName equals x.Name into g
from x in g.DefaultIfEmpty()
orderby x.SourceId
select new
{
SourceId=x.SourceId ?? 0,
TargetId=x.TargetID ?? 0,
Name = svName,
DiffPerc = x.DiffPerc
}
).ToList()
};
更新： 根据评论，这是示例输入和预期输出：
案例 1:当所有父变体的子变体名称不同时
变体：
Id Name Type CategoryId
11 Variant1 Add 1
12 Variant2 Add 1
13 Variant3 Add 1
14 Variant4 Add 1
子变量：
Id VariantId Name
66 11 Abc
67 11 PQR
68 11 Xyz
70 12 lmn
71 12 xxx
72 12 hhh
试运行：
Id TestId SourceSubVariantId TargetSubVariantId DiffPerc
114 100 66 67 10.00
115 100 67 68 20.00
114 100 70 71 40.00
115 100 71 72 50.00
预期输出：
情况 2:当子变体名称在所有父变体中都相同时:
子变量：
Id VariantId Name
66 11 Abc
67 11 PQR
68 11 Xyz
70 12 Abc
71 12 PQR
72 12 Xyz
预期输出：
我们在聊天中进行了一些讨论，直到我明白了你想要什么。
这是代码：
class Program
{
static void Main(string[] args)
{
VariantsEntities db=new VariantsEntities();
var queryResult = db.Variants.AsEnumerable().Select(x => new PageViewModel
{
ParentVariant = x.Name,
Type = x.Type,
CustomSubvariantList = GetCustomSubVariants(x.Id,db).ToList()
}).ToList();
var jsonObj = JsonConvert.SerializeObject(queryResult);
Console.WriteLine(jsonObj);
Console.ReadKey();
}
private static IEnumerable<Customsubvariantlist> GetCustomSubVariants(int variantId, VariantsEntities db)
{
var subVariants = db.SubVariants.ToList();
foreach (var subVariant in subVariants)
{
var obj=new Customsubvariantlist();
obj.Name = subVariant.Name;
var testOpTarget = db.TestOperations
.FirstOrDefault(x => x.TargetSubVariantId == subVariant.Id);
var testOpSource = db.TestOperations
.FirstOrDefault(x => x.SourceSubVariantId == subVariant.Id);
if (subVariant.VariantId == variantId)
{
obj.Value = testOpTarget == null ?
testOpSource?.SourceValue : testOpTarget?.TargetValue;
obj.DiffPerc = testOpTarget?.DiffPerc;
}
else
{
obj.Value = null;
obj.DiffPerc = null;
}
yield return obj;
}
}
}
您只需要替换DbContext 名称，然后进行测试即可。
这是结果：
[
{
"ParentVariant": "Variant1",
"Type": "Add",
"CustomSubvariantList": [
{
"Name": "Abc",
"Value": 200,
"DiffPerc": null
},
{
"Name": "Pqr",
"Value": 300,
"DiffPerc": 100.0
},
{
"Name": "xyz",
"Value": 500,
"DiffPerc": 200.0
},
{
"Name": "lmn",
"Value": null,
"DiffPerc": null
},
{
"Name": "xxx",
"Value": null,
"DiffPerc": null
},
{
"Name": "hhh",
"Value": null,
"DiffPerc": null
}
]
},
{
"ParentVariant": "Variant2",
"Type": "Add",
"CustomSubvariantList": [
{
"Name": "Abc",
"Value": null,
"DiffPerc": null
},
{
"Name": "Pqr",
"Value": null,
"DiffPerc": null
},
{
"Name": "xyz",
"Value": null,
"DiffPerc": null
},
{
"Name": "lmn",
"Value": 1000,
"DiffPerc": null
},
{
"Name": "xxx",
"Value": 2000,
"DiffPerc": 1000.0
},
{
"Name": "hhh",
"Value": 4000,
"DiffPerc": 2000.0
}
]
}
]
您可以从 here 下载示例项目。这个项目是用你发给我的示例数据库完成的，数据库优先也是如此，一些道具或表格可能有不同的名称，请在你的项目中移动代码之前检查这一点。
基本上我做了什么：
创建了一个新的控制台应用程序项目
我从你的 json 对象中得到了模型（我复制了 json 对象并将其粘贴到 class 中，使用（vs 菜单）编辑 - > 过去特别 -> 过去 JSON 为 类。
因为你想要每个
Varian的所有SubVariants，我创建了一个单独的方法来处理你创建CustomSubVariantList的规则。在这种方法中，我迭代抛出所有 SubVariants 并根据您的条件创建对象。
更新： 您在一次查询中的解决方案：
static void Main(string[] args)
{
VariantsEntities db = new VariantsEntities();
var result = from x in db.Variants
select new PageViewModel
{
ParentVariant = x.Name,
Type = x.Type,
CustomSubvariantList = (from z in db.SubVariants
let testOpTarget=z.TestOperations1
.FirstOrDefault(q=>q.TargetSubVariantId==z.Id)
let testOpSource=z.TestOperations
.FirstOrDefault(q=>q.SourceSubVariantId==z.Id)
select new Customsubvariantlist
{
Name = z.Name,
Value = x.Id==z.VariantId?
testOpTarget.TargetValue??
testOpSource.SourceValue:null,
DiffPerc = x.Id==z.VariantId?
testOpTarget.DiffPerc:null
}).ToList()
};
var json = JsonConvert.SerializeObject(result.ToList());
Console.WriteLine(json);
Console.ReadKey();
}
此查询产生与上述方法相同的结果。 请让我知道您是否需要！！
更新：这是案例 2 的查询
var result = from x in db.Variants
select new PageViewModel
{
ParentVariant = x.Name,
Type = x.Type,
CustomSubvariantList = (from z in db.SubVariants.GroupBy(g => g.Name)
.Select(g => g.FirstOrDefault(d => d.VariantId == x.Id) ?? g.FirstOrDefault())
let testOpTarget = z.TestOperations1
.FirstOrDefault(q => q.TargetSubVariantId == z.Id)
let testOpSource = z.TestOperations
.FirstOrDefault(q => q.SourceSubVariantId == z.Id)
select new Customsubvariantlist
{
Name = z.Name,
SubVariantId = z.Id,
CombineName =(z.TestOperations.Any() || z.TestOperations1.Any())?
testOpTarget.TargetValue.HasValue?
testOpTarget.SubVariant.Name+" to "+testOpTarget.SubVariant1.Name : null: "Undefined",
Value = x.Id == z.VariantId
? testOpTarget.TargetValue ??
testOpSource.SourceValue
: null,
DiffPerc = x.Id == z.VariantId
? testOpTarget.DiffPerc
: null
}).OrderBy(k => k.SubVariantId).ToList()
};
这是您的查询的 "variant".. 它提取所有 SubVariants 每个 Variant(s) 的顺序，因为它们在 table SubVariants 中（通过它们的自动种子 Sql Server Identity Id)，不考虑涉及的 TestOperation 并避免重复作为您的预期输出。
不幸的是，不可能始终将所有子变量指定为源和目标子变量，因为此信息取决于测试操作，实际上测试操作决定子变量是 "source" 还是 "target"。因此，如果某些子变体未包含在测试操作 records/entity 中，则它们不能作为源或目标出现。解决方法可能是附加到返回的匿名类型 "Name" 属性 旁边，还有 "Id SubVar"
我添加了 2 个 DTO，因为 entity framework 不允许使用 distinct().ToList() 方法来保留顺序和应用自定义不同规则，所以我添加了一个步骤以从 Link 传递到Link 处的 EF 通过 dto 对象来对象，并以这种方式使应用不同的自定义规则成为可能..
public class CustomerVariantDTO
{
public String Type;
public String ParentVariant;
public IEnumerable<CustomerSubVariantDTO> CustomSubvariantList;
}
public class CustomerSubVariantDTO
{
public int? VariantId;
public int? SubVariantId;
public int? SourceId;
public int? TargetId;
public String Name;
public Decimal? DiffPerc;
}
sealed class CustomerSubVariantDTOComparer : IEqualityComparer<CustomerSubVariantDTO>
{
public int GetHashCode(CustomerSubVariantDTO obj)
{
return 0;
}
public bool Equals(CustomerSubVariantDTO x, CustomerSubVariantDTO y)
{
return x.SourceId == y.SourceId &&
x.TargetId == y.TargetId &&
x.Name == y.Name &&
x.DiffPerc == y.DiffPerc;
}
}
public void DoTestOfCustomerVariantDTO()
{
int testId = 1;
using (var context = new VariantsEntities())
{
var query =
(from v in context.Variants
where v.Type == "Add"
select new CustomerVariantDTO
{
ParentVariant = v.Name,
Type = v.Type,
CustomSubvariantList =
(
from sv in context.SubVariants.Select(sv => sv)
join x in
(
from svparent in v.SubVariants
from to in svparent.TestOperation
where to.TestId == testId
select new
{
svparent.Name,
to.DiffPerc,
SourceId = (int?)to.SubVariants.Id ?? 0,
TargetId = (int?)to.SubVariants1.Id ?? 0
}
)
on sv.Name equals x.Name into g
from x in g.DefaultIfEmpty()
select new CustomerSubVariantDTO{
VariantId = sv.VariantId,
SubVariantId = sv.Id,
SourceId = (int?)x.SourceId ?? sv.TestOperation.Select(to => to.SourceSubVariantId).FirstOrDefault(),
TargetId = (int?)x.TargetId ?? sv.TestOperation.Select(to => to.TargetSubVariantId).FirstOrDefault(),
Name = sv.Name,
DiffPerc = x.DiffPerc
}
).OrderBy(csv => new { csv.VariantId, csv.SubVariantId })
}).ToList();
var listCustomVariants =
query.Select(v => new{
Type = v.Type,
ParentVariant = v.ParentVariant,
CustomSubvariantList = v.CustomSubvariantList.Distinct(new CustomerSubVariantDTOComparer()).ToList()
});
foreach (var item in listCustomVariants){
Console.WriteLine($"Type: {item.Type} - ParentVariant: {item.ParentVariant} ");
foreach (var csubvar in item.CustomSubvariantList)
Console.WriteLine($"SourceId: {csubvar.SourceId} - TargetiId: {csubvar.TargetId} - NAme: {csubvar.Name} - DiffPerc: {csubvar.DiffPerc} ");
}
}
}