dapper - Dapper：直接从 GridReader 读取第 n 个项目

Question

这是我在 dapper 博客中发现的

var sql = 
@"
select * from Customers where CustomerId = @id
select * from Orders where CustomerId = @id
select * from Returns where CustomerId = @id";

using (var multi = connection.QueryMultiple(sql, new {id=selectedId}))
{
   var customer = multi.Read<Customer>().Single();      
   var returns = multi.Read<Return>().ToList();
   var orders = multi.Read<Order>().ToList();
   ...
} 

我的要求是我想直接阅读 "orders" 。我可以这样做吗？

Answer 1

如果你不想要另外两个，你可以Read在不迭代该序列的情况下调用：不会物化任何对象：

var customer = multi.Read<Customer>(); // not consumed
var returns = multi.Read<Return>(); // not consumed
var orders = multi.Read<Order>().ToList();

Answer 2

您可以使用查询扩展来读取单个，例如

const string sql = "select * from Orders where CustomerId = @id";
var orders = connection.Query<Order>(sql, new {id = 1}).ToList(); 

编辑：

执行存储过程：

var orders = connection.Query<Order>("GetOrders", new {id = 1}, commandType: CommandType.StoredProcedure).ToList();