Entity framework core 实体框架核心-迁移从模型中创建所有属性,而不是所需的属性
这是我在EfCore的开始(早些时候我在nHibernate和Dapper)。 我对映射有问题 我的模型是这样的:Entity framework core 实体框架核心-迁移从模型中创建所有属性,而不是所需的属性,entity-framework-core,mapping,ef-core-2.0,columnmappings,Entity Framework Core,Mapping,Ef Core 2.0,Columnmappings,这是我在EfCore的开始(早些时候我在nHibernate和Dapper)。 我对映射有问题 我的模型是这样的: public class Document { public Guid Id {get;set;} public string Name {get;set;} public int ValueIDontWantToBeInDb {get; set;} } 我的映射: b.ToTable("documents"); b.Property(x => x.Id
public class Document
{
public Guid Id {get;set;}
public string Name {get;set;}
public int ValueIDontWantToBeInDb {get; set;}
}
我的映射:
b.ToTable("documents");
b.Property(x => x.Id).ValueGeneratedOnAdd();
b.HasKey(x => x.Id);
b.Property(x => x.Name).IsRequired();
(其中b是在IEntityTypeConfiguration实现中接收到的EntityTypeBuilder
如您所见,我从未使用ValueIDontWantToBeInDb,但EfCore一直在将其添加到表架构中。为什么会这样,以及如何使其仅添加我想要的属性
我知道有一个Ignore方法,但我必须在每个属性上的每个模型上调用它,我不想添加到模式中
我只想向EfCore展示“嘿,像这样映射这些属性”-就像在nHibernate中一样。如何做到这一点?好的,我为此创建了一些解决方案。但我认为EfCore在标准中没有这样的解决方案,这真的是出人意料。因此,首先为所有映射创建基类。这真是一个充满魔力的地方:
abstract class BaseMap<T>: IEntityTypeConfiguration<T> where T: class, IDbItem //IDbItem is my own constraint, just an interface that has Id property
{
EntityTypeBuilder<T> theBuilder;
List<string> mappedPropertyNames = new List<string>();
protected PropertyBuilder<TProperty> Map<TProperty>(Expression<Func<T, TProperty>> x) //this will be called instead of Property()
{
mappedPropertyNames.Add(GetPropertyName(x));
return theBuilder.Property(x);
}
protected ReferenceNavigationBuilder<T, TRelatedEntity> HasOne<TRelatedEntity>(Expression<Func<T, TRelatedEntity>> x)
where TRelatedEntity: class
{
mappedPropertyNames.Add(GetPropertyName(x));
return theBuilder.HasOne(x);
}
protected CollectionNavigationBuilder<T, TRelatedEntity> HasMany<TRelatedEntity>(Expression<Func<T, IEnumerable<TRelatedEntity>>> x)
where TRelatedEntity: class
{
mappedPropertyNames.Add(GetPropertyName(x));
return theBuilder.HasMany(x);
}
protected PropertyBuilder<TColumnType> Map<TColumnType>(string propName)
{
mappedPropertyNames.Add(propName);
return theBuilder.Property<TColumnType>(propName);
}
protected abstract void CreateModel(EntityTypeBuilder<T> builder);
public void Configure(EntityTypeBuilder<T> builder)
{
theBuilder = builder;
Map(x => x.Id).ValueGeneratedOnAdd();
builder.HasKey(x => x.Id);
CreateModel(builder);
IgnoreUnmappedProperties(builder);
}
void IgnoreUnmappedProperties(EntityTypeBuilder<T> builder)
{
PropertyInfo[] propsInModel = typeof(T).GetProperties(BindingFlags.Instance | BindingFlags.Public);
foreach (var prop in propsInModel)
{
if (!mappedPropertyNames.Contains(prop.Name))
{
builder.Ignore(prop.Name);
}
}
}
string GetPropertyName<TProperty>(Expression<Func<T, TProperty>> memberExpression)
{
MemberExpression member = null;
switch (memberExpression.Body)
{
case UnaryExpression ue when ue.Operand is MemberExpression:
member = ue.Operand as MemberExpression;
break;
case MemberExpression me:
member = me;
break;
default:
throw new InvalidOperationException("You should pass property to the method, for example: x => x.MyProperty");
}
var pInfo = member.Member as PropertyInfo;
if (pInfo == null)
throw new InvalidOperationException("You should pass property to the method, for example: x => x.MyProperty");
return pInfo.Name;
}
}
class DocumentMap : BaseMap<Document>
{
protected override void CreateModel(EntityTypeBuilder<Document> b)
{
b.ToTable("documents");
Map(x => x.Name).IsRequired();
Map<Guid>("Owner_id").IsRequired();
HasOne(x => x.Owner)
.WithMany()
.HasForeignKey("Owner_id")
.HasConstraintName("FK_Users_Documents")
.IsRequired()
.OnDelete(DeleteBehavior.Cascade);
HasMany(x => x.Periods)
.WithOne(y => y.ParentDocument);
HasMany(x => x.Loans)
.WithOne(y => y.ParentDocument);
}
}
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
builder.ApplyConfigurationsFromAssembly(Assembly.GetExecutingAssembly());
}