对多个字段的外键约束 [英] Foreign key constraint to multiple fields
问题描述
Mates，
我有一个SQL Server表< entity>这是在一定的管理。表< entity>与< entitystatus>有关系。
< entity>
Id（int，PK，auto-increment）
AdminstrationId int
状态int
名称varchar
....
< entitystatus>
Id（int，PK，auto-increment）
AdminstrationId int
Number int
名称varchar
正如您所看到的，两个表都有一个Id字段，它是PK并且自动递增。
现在我希望实体框架在两个AdministrationId字段和< entity> .Status&之间创建关系。 < entitystatus>数字字段。
我该怎么做？
下面的代码你试过什么，实际上适用于关系，但它将Id字段作为状态表的PK删除。当我在< entitystatus>中输入新的状态值时，这会导致错误。桌子
我尝试过：
Mates,
I have a SQL Server table <entity> which is in a certain administration. The table <entity> has a relation with <entitystatus>.
<entity>
Id (int, PK, auto-increment)
AdminstrationId int
Status int
Name varchar
....
<entitystatus>
Id (int, PK, auto-increment)
AdminstrationId int
Number int
Name varchar
As you can see, both tables have a Id field which is a PK and have auto-increment on.
Now I want entity framework to create a relation between both AdministrationId fields, and the <entity>.Status & <entitystatus>Number field.
How can I do this?
The code below in the 'what have you tried', actually works for the relation, but it removes the Id field as a PK of the status table. This causes an error when I enter new status values in the <entitystatus> table
What I have tried:
modelBuilder.Entity<Entity>()
.HasKey(c => new { c.AdministrationId, c.Number });
modelBuilder.Entity<Entity>()
.HasRequired(p => p.EntityStatus)
.WithMany(x => x.Entities)
.HasForeignKey(p => new { p.AdministrationId, p.Status });
推荐答案
我通常在SQL实用程序（例如SQL Server Management Studio）中为SQL构建表/关系。 br />
除此之外，我仍然会遵循相同的路径：创建表，设置主键和关系作为谨慎的SQL查询，而不是参数化C＃代码。
我更喜欢让SQL处理SQL（即使通过C＃，C ++，php，......）
建立SQL连接
设置查询字符串
执行它们
I usually build tables/relationships for SQL in a SQL utility (such as SQL Server Management Studio).
That aside, I would still following something of the same route: create the tables, set primary key(s), and the relationships as discreet SQL Queries and not parametized with C# code.
I prefer letting SQL handle SQL (even if via C#, C++, php, ...)
Establish a SQL connection
Set the Query Strings
Execute them
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