ActiveRecord返回部分字段的查询

1. 自定义非受管实体类

namespace IOT{

　　public class CustomerProjection{

　　　　public int ID = 0;

　　　　public string Name = "";
　　　　public CustomerProjection(int id, string name){

　　　　　　ID = id;

　　　　　　Name = name;
　　　　}

　　}

}

 

2. 在实体类属性添加对自定义非受管实体类的引入

[Imprt(typeof(IOT.CustomerProjection), "CustomerProjection")]

[ActiveRecord("Customers")]

public class Customer : ActiveRecordBase<Customer>

{

 

    [PrimaryKey(PrimaryKeyType.Assigned)]

    public string CustomerID

    {

        get { return customerID; }

        set { customerID = value; }

    }

    .....

 }

 

3. 在代码中用检索字段生成自定义非受管实体类

protected void Page Load(object sender, EventArgs e)

{

    IActiveRecordQuery query = new HqlBasedQuery(typeof (Customer),

        @"select new CustomerProjection(c.CustomerID, c.CompanyName)

             from Customer c join c.Orders o where c.Country = 'USA'

           group by c.CustomerID, c.CompanyName, c.City, c.Region

        ");

    GridView1.DataSource = ActiveRecordMediator.ExecuteQuery(query);

    GridView1.DataBind();

}