Dapper 简单映射
本文关键字:映射 简单 Dapper | 更新日期: 2023-09-27 18:31:10
Table:
create table Documents
(Id int,
SomeText varchar(100),
CustomerId int,
CustomerName varchar(100)
)
insert into Documents (Id, SomeText, CustomerId, CustomerName)
select 1, '1', 1, 'Name1'
union all
select 2, '2', 2, 'Name2'
类:
public class Document
{
public int Id { get; set; }
public string SomeText { get; set; }
public Customer { get; set; }
}
public class Customer
{
public int Id { get; set; }
public string Name { get; set; }
}
我怎样才能通过 Dapper 获得他们Customers
的所有Documents
?这给了我所有文档,但客户是空的(当然):
connection.Query<Document>("select Id, SomeText, CustomerId, CustomerName from Documents")...
编辑 - 类似但更高级的映射问题:Dapper 中间映射
取自 dapper 项目页面的示例(请参阅多映射部分):
var sql =
@"select * from #Posts p
left join #Users u on u.Id = p.OwnerId
Order by p.Id";
var data = connection.Query<Post, User, Post>(sql, (post, user) => { post.Owner = user; return post;});
var post = data.First();
post.Content.IsEqualTo("Sams Post1");
post.Id.IsEqualTo(1);
post.Owner.Name.IsEqualTo("Sam");
post.Owner.Id.IsEqualTo(99);
var docs = connection.Query<Document, Customer, Document>(
"select Id, SomeText, CustomerId as [Id], CustomerName as [Name] from Documents",
(doc, cust) => { doc.Customer = cust; return doc; }).ToList();