MVC 3 Model for many to many table using Entity Framework
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30-06-2021 - |
문제
I want to simply select the Version and Template combinations that are in the db.
Here is the db structure:
CREATE Table ProductVersion(
id int not null primary key Identity,
Product_ID int not null,
Version decimal(18,1) not null,
Active bit not null,
LicenseVersion int not null,
FOREIGN KEY (Product_ID) References Products(id)
)
Create Table CodeTemplates(
id int not null primary key Identity,
Name varchar(50) not null,
DLT_ID int not null,
QuantityRule_ID int,
SerialRule_ID int,
DurationRule_ID int,
foreign key (DLT_ID) References DisplayedLicenseTypes(id),
foreign key (QuantityRule_ID) References Rulesets(id),
foreign key (SerialRule_ID) References Rulesets(id),
foreign key (DurationRule_ID) References Rulesets(id)
)
CREATE table ProductVersion_CodeTemplate(
ProductVersion_ID int not null,
CodeTemplate_ID int not null,
CONSTRAINT PK_Restrictions Primary Key Clustered
(
ProductVersion_ID asc,
CodeTemplate_ID asc
),
foreign key (ProductVersion_ID) References ProductVersion(id),
foreign key (CodeTemplate_ID) References CodeTemplates(id)
)
Here are the current models in use for productversion and CodeTemplates:
[Table("ProductVersion")]
public class ProductVersionModel
{
public int ID { get; set; }
public virtual ProductModel Product { get; set; }
[DisplayFormat(DataFormatString = "{0:F1}",ApplyFormatInEditMode=true)]
public decimal Version { get; set; }
public bool Active { get; set; }
public int LicenseVersion { get; set; }
}
[Table("CodeTemplates")]
public class TemplateModel
{
public int ID { get; set; }
public string Name { get; set; }
public virtual DisplayedLicenseTypeModel DLT { get; set; }
public virtual List<LicenseFlagModel> LicenseFlags { get; set; }
public virtual RulesetModel QuantityRule { get; set; }
public virtual RulesetModel SerialRule { get; set; }
public virtual RulesetModel DurationRule { get; set; }
}
Here is what I attempted to use:
[Table("ProductVersion_CodeTemplate")]
public class ProductVersionWithTemplateModel
{
[Key, Column(Order = 0)]
public virtual ProductVersionModel ProductVersion { get; set; }
[Key, Column(Order = 1)]
public virtual TemplateModel CodeTemplate { get; set; }
}
First error that pops up is:
One or more validation errors were detected during model generation:
System.Data.Edm.EdmEntityType: : EntityType 'ProductVersionWithTemplateModel' has no key defined. Define the key for this EntityType. System.Data.Edm.EdmEntitySet: EntityType: EntitySet �AppliedTemplates� is based on type �ProductVersionWithTemplateModel� that has no keys defined.
What am I missing here, a dbmodelbuilder binding?
ANSWER (since the formatting is terrible in a comment):
[Table("ProductVersion_CodeTemplate")]
public class ProductVersionWithTemplateModel
{
[Key, Column(Order = 0)]
public int ProductVersion_ID { get; set; }
[ForeignKey("ProductVersion_ID")]
public virtual ProductVersionModel ProductVersion { get; set; }
[Key, Column(Order = 1)]
public int CodeTemplate_ID { get; set; }
[ForeignKey("CodeTemplate_ID")]
public virtual TemplateModel CodeTemplate { get; set; }
}
해결책
Perhaps you should be including a reference like this:
[Table("ProductVersion_CodeTemplate")]
public class ProductVersionWithTemplateModel
{
[Key, Column(Order = 0)]
public int ProductVersionModelId { get; set; }
[ForeignKey("ProductVersionModelId")]
public virtual ProductVersionModel ProductVersion { get; set; }
[Key, Column(Order = 1)]
public int TemplateModelId { get; set; }
[ForeignKey("TemplateModelId")]
public virtual TemplateModel CodeTemplate { get; set; }
}