對映超過 7 種型別
有時,你對映的型別數量超過了構造構造的 Func <>所提供的數量。
我們將提供要對映到陣列的型別,然後是對映函式,而不是將 Query<>
與泛型型別引數輸入一起使用。除了初始手動設定和轉換值之外,其餘功能不會更改。
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");