映射超过 7 种类型

有时,你映射的类型数量超过了构造构造的 Func <>所提供的数量。

我们将提供要映射到数组的类型,然后是映射函数,而不是将 Query<> 与泛型类型参数输入一起使用。除了初始手动设置和转换值之外,其余功能不会更改。

            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>(sql,
    new[]
    {
        typeof(Person),
        typeof(Country),
        typeof(Book)
    }
    , obj => {

        Person person = obj[0] as Person;
        Country country = obj[1] as Country;
        Book book = obj[2] as 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");