如何第一映射实体框架代码列不同数据类型的实体属性格式 [英] How to map column and entity propery of different datatypes in entity framework code first
问题描述
我使用实体框架。5 - 代码第一个
我有我连接到一个已经存在有一段时间了一个数据库(我没有创建它)。有一个名为 T_Customers表
。它包含了所有客户的名单。它具有以下结构(仅部分示出):
CUSTOMER_ID |数字(5,0)|自动递增| NOT NULL(未设置主键)
FName参数| VARCHAR(50)|不为空
LName的| VARCHAR(50)|不为空
我的客户
类:
公共类客户:IEntity
{
公众诠释标识{搞定;组; }
公共字符串名字{获得;组; }
公共字符串名字{获得;组; }
}
我的 IEntity
接口:
公共接口IEntity
{
INT标识{搞定;组; }
}
我在我的数据库上下文类以下内容:
公共类DatabaseContext:的DbContext
{
公共DatabaseContext(字符串的connectionString)
:底座(的connectionString)
{
}
公共DbSet<客户>客户{搞定;组; }
保护覆盖无效OnModelCreating(DbModelBuilder模型构建器)
{
modelBuilder.Configurations.Add(新CustomerConfiguration());
}
公开新DbSet< TEntity> SET< TEntity>()
其中TEntity:类,IEntity
{
返回base.Set< TEntity>();
}
}
我的客户配置类:
类CustomerConfiguration:EntityTypeConfiguration<客户>
{
内部CustomerConfiguration()
{
this.ToTable(T_Customers);
this.Property(X => x.Id).HasColumnName(CUSTOMER_ID);
this.Property(X => x.FirstName).HasColumnName(FName参数);
this.Property(X => x.LastName).HasColumnName(LName的);
}
}
我想在我的实体声明一致我需要所有的ID是整数。此客户ID是在数据库类型的数字,并试图返回所有的客户列表时,现在我遇到的问题。我如何从数据库数值类型到C#整数类型映射?我不会改变我的课的ID可空或小数,我的ID始终不为空的和整数。我也无法更改数据库
这是我收到的错误是:
在客户的id属性不能被设置为十进制的价值。
必须将此属性设置为类型的非空值的Int32。
指定数值类型列
属性(X => x.Id).HasColumnName(CUSTOMER_ID)HasColumnType(数字)。
在生成的数据库,它会创建一个精确的数字列 18,0
。但是,当你映射到现有的数据库,它会正常工作与 5,0
数字列。
I am using Entity Framework 5 - Code first.
I have a database that I am connecting to that already exists for some time now (I did not create it). There is a table called T_Customers
. It contains a list of all the customers. It has the following structure (only partially shown):
Customer_id | numeric (5, 0) | auto increment | not null (not set as primary key)
FName | varchar(50) | not null
LName | varchar(50) | not null
My Customer
class:
public class Customer : IEntity
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
My IEntity
interface:
public interface IEntity
{
int Id { get; set; }
}
I have the following in my database context class:
public class DatabaseContext : DbContext
{
public DatabaseContext(string connectionString)
: base(connectionString)
{
}
public DbSet<Customer> Customers { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new CustomerConfiguration());
}
public new DbSet<TEntity> Set<TEntity>()
where TEntity : class, IEntity
{
return base.Set<TEntity>();
}
}
My customer configuration class:
class CustomerConfiguration : EntityTypeConfiguration<Customer>
{
internal CustomerConfiguration()
{
this.ToTable("T_Customers");
this.Property(x => x.Id).HasColumnName("Customer_id");
this.Property(x => x.FirstName).HasColumnName("FName");
this.Property(x => x.LastName).HasColumnName("LName");
}
}
I'm trying to be consistent in my entity declarations, I need all the IDs to be integers. This customer ID is of type numeric in the database, and now I am running into issues when trying to return a list of all the customers. How do I map from a database numeric type to a C# integer type? I'm not changing my class's ID to nullable or decimal, my IDs are always non nullable and integer. I also cannot change the database.
The error that I am getting is:
The 'Id' property on 'Customer' could not be set to a 'Decimal' value.
You must set this property to a non-null value of type 'Int32'.
Specify numeric type for column
Property(x => x.Id).HasColumnName("Customer_id").HasColumnType("numeric");
When generating database, it will create numeric column with precision 18,0
. But when you are mapping to existing database, it will work fine with 5,0
numeric column.
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