[英]Custom Convention for table with Prefix Entity Framework
All my POCO classes have two letter prefix LK_. 我所有的POCO类都有两个字母前缀LK_。 Entity framework conventions for primary & foreign keys would not work. 主键和外键的实体框架约定不起作用。 Considering I have ~200 classes to decorate with Key or ForeignKey attribute its a cumbersome process & does not sound like a smart way of doing it. 考虑到我有200个要用Key或ForeignKey属性进行装饰的类,这是一个麻烦的过程,而且听起来并不明智。
Could you please suggest custom convention? 您能建议自定义约定吗?
public class LK_Employee
{
public Guid EmployeeID {get; set;}
public string Name {get; set;}
}
public class LK_Company
{
public Guid CompanyID {get; set;}
public string Name {get; set;}
}
public class LK_Employee_LK_Company
{
public Guid EmployeeID {get; set;}
public Guid CompanyID{get; set;}
}
This will set any filed like LK_TableName
as the table's primary key, when there is a simple column key: 当有一个简单的列键时,这会将诸如LK_TableName
之类的任何文件设置为表的主键:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Properties<Guid>()
.Where(p => "LK_" + p.Name == p.DeclaringType.Name + "Id")
.Configure(p => p.IsKey());
}
To support composite keys, as well as simple kesy, you need to do this: 要支持复合键以及简单的kesy,您需要执行以下操作:
// Counter: keeps track of the order of the column inside the composite key
var tableKeys = new Dictionary<Type,int>();
modelBuilder.Properties<Guid>()
.Where(p =>
{
// Break the entiy name in segments
var segments = p.DeclaringType.Name.Split(new[] {"LK_","_LK_"},
StringSplitOptions.RemoveEmptyEntries);
// if the property has a name like one of the segments, it's part of the key
if (segments.Any(s => s + "ID" == p.Name))
{
// If it's not already in the column counter, adds it
if (!tableKeys.ContainsKey(p.DeclaringType))
{
tableKeys[p.DeclaringType] = 0;
}
// increases the counter
tableKeys[p.DeclaringType] = tableKeys[p.DeclaringType] + 1;
return true;
}
return false;
})
.Configure(a =>
{
a.IsKey();
// use the counter to set the order of the column in the composite key
a.HasColumnOrder(tableKeys[a.ClrPropertyInfo.DeclaringType]);
});
Creating the convention for foreing keys is much more complex. 创建前键的约定要复杂得多。 You can have a look at EF6 convention in this route: / src/ EntityFramework.Core/ Metadata/ Conventions/ Internal/ ForeignKeyPropertyDiscoveryConvention.cs
, on EF6 github . 您可以在以下路径中查看EF6约定: / src/ EntityFramework.Core/ Metadata/ Conventions/ Internal/ ForeignKeyPropertyDiscoveryConvention.cs
,在EF6 github上 。 And see the tests for illustration of use: / test/ EntityFramework.Core.Tests/ Metadata/ ModelConventions/ ForeignKeyPropertyDiscoveryConventionTest.cs
并查看测试以获取使用说明: / test/ EntityFramework.Core.Tests/ Metadata/ ModelConventions/ ForeignKeyPropertyDiscoveryConventionTest.cs
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