小巧玲珑multimapping和左的连接
问题描述:
鉴于这种测试:小巧玲珑multimapping和左的连接
public class Author
{
public int AuthorId { get; set; }
public List<Book> Books { get; set; } = new List<Book>();
}
public class Book
{
public int BookId { get; set; }
}
[Fact]
public async Task DapperCollapseLeftJoin()
{
var sql = @" select 1 as AuthorId, 1 as BookId
union select 1 as AuthorId, 2 as BookId
union select 2 as AuthorId, 3 as BookId
union select 2 as AuthorId, 4 as BookId";
var authorsWithBooks =
(await AC.OpenConnection.QueryAsync<Author, Book, Author>(sql,
(author, book) => { author.Books.Add(book); return author; },
splitOn: "AuthorId, BookId")).ToList();
// fails because we're getting 4 author+book rows
Assert.Equal(2, authorsWithBooks.Count);
}
为精致小巧的文件说multimapping地图行至多个对象并没有提及实际上倒塌的物体(会发生左/内部联接那里像什么重复最左列值)。
有没有一种巧妙的方式来实现这一点?