c# - 使用 Dapper 查询复杂对象

Question

我有一个具有以下属性的 Customer 类:

public int Id { get; set; }
public string Name { get; set; }
public int AddressId { get; set; }
public Address Address { get; set; }

我的目标是编写一个 Dapper 查询，该查询将使用内部联接来填充每个返回的客户中的整个地址属性。

这是我所拥有的，它正在工作，但我想知道这是否是最干净/最简单的方法:

StringBuilder sql = new StringBuilder();
using (var conn = GetOpenConnection())
{
    sql.AppendLine("SELECT c.Id, c.Name, c.AddressId, a.Address1, a.Address2, a.City, a.State, a.ZipCode ");
    sql.AppendLine("FROM Customer c ");
    sql.AppendLine("INNER JOIN Address a ON c.AddressId = a.Id ");

    return conn.Query<Customer, Address, Customer>(
        sql.ToString(),
        (customer, address) => {
            customer.Address= address;
            return userRole;
        },
        splitOn: "AddressId"
    ).ToList();
}

我对添加另一个属性有些担心，例如:

public Contact Contact { get; set; }

我不确定如何切换上面的语法来填充地址和联系人。

Answer 1

我使用 Dapper 1.40 版进行编码，并且编写了如下所示的查询，我没有任何问题可以填充一个以上的对象，但我遇到了 8 个我可以映射的不同类的限制一个问题。

public class Customer {
    public int Id { get; set; }
    public string Name { get; set; }
    public int AddressId { get; set; }  
    public int ContactId { get; set; }
    public Address Address { get; set; }
    public Contact Contact { get; set; }
}

public class Address {
    public int Id { get; set; }
    public string Address1 {get;set;}
    public string Address2 {get;set;}
    public string City {get;set;}
    public string State {get;set;}
    public int ZipCode {get;set;}
    public IEnumerable<Customer> Customer {get;set;}
}

public class Contact {
    public int Id { get; set; }
    public string Name { get; set; }
    public IEnumerable<Customer> Customer {get;set;}
}

using (var conn = GetOpenConnection())
{
    var query = _contextDapper
        .Query<Customer, Address, Contact, Customer>($@"
            SELECT c.Id, c.Name, 
                c.AddressId, a.Id, a.Address1, a.Address2, a.City, a.State, a.ZipCode,
                c.ContactId, ct.Id, ct.Name
            FROM Customer c
            INNER JOIN Address a ON a.Id = c.AddressId
            INNER JOIN Contact ct ON ct.Id = c.ContactId", 
            (c, a, ct) =>
            {
                c.LogType = a;
                c.Contact = ct;
                return c; 
            }, splitOn: "AddressId, ContactId")
        .AsQueryable();

    return query.ToList();          
}