Dapper 一对多查询 one to many

参考文档:dapper one to many

table

public class person
{
    public int id { get; set; }
    public string name { get; set; }
    public int born { get; set; }
    public country residience { get; set; }
    public icollection<book> books { get; set; }
}

public class country
{
    public int countryid { get; set; }
    public string countryname { get; set; }
}

public class book
{
    public int bookid { get; set; }
    public string bookname { get; set; }
}

c# code

pulic list<person> getpersons(){
 var sql = @"select 1 as id, 'daniel dennett' as name, 1942 as born, 1 as countryid, 'united states of america' as countryname, 1 as bookid, 'brainstorms' as bookname
union all select 1 as id, 'daniel dennett' as name, 1942 as born, 1 as countryid, 'united states of america' as countryname, 2 as bookid, 'elbow room' as bookname
union all select 2 as id, 'sam harris' as name, 1967 as born, 1 as countryid,  'united states of america' as countryname, 3 as bookid, 'the moral landscape' as bookname
union all select 2 as id, 'sam harris' as name, 1967 as born, 1 as countryid,  'united states of america' as countryname, 4 as bookid, 'waking up: a guide to spirituality without religion' as bookname
union all select 3 as id, 'richard dawkins' as name, 1941 as born, 2 as countryid,  'united kingdom' as countryname, 5 as bookid, 'the magic of reality: how we know what`s really true' as bookname
union all select 3 as id, 'richard dawkins' as name, 1941 as born, 2 as countryid,  'united kingdom' as countryname, 6 as bookid, 'an appetite for wonder: the making of a scientist' as bookname";

var remaininghorsemen = new dictionary<int, person>();
connection.query<person, country, book, person>(sql, (person, country, book) => {
    //person
    person personentity;
    //trip
    if (!remaininghorsemen.trygetvalue(person.id, out personentity))
    {
        remaininghorsemen.add(person.id, personentity = person);
    }

    //country
    if(personentity.residience == null)
    {
        if (country == null)
        {
            country = new country { countryname = "" };
        }
        personentity.residience = country;
    }                    

    //books
    if(personentity.books == null)
    {
        personentity.books = new list<book>();
    }

    if (book != null)
    {
        if (!personentity.books.any(x => x.bookid == book.bookid))
        {
            personentity.books.add(book);
        }
    }

    return personentity;
}, 
spliton: "countryid,bookid");

return remaininghorsemen.value.tolist(); 
}