public static void Video6_3_Joining_Data_With_Query_Syntax_Start()
{
Console.WriteLine("");
Console.WriteLine("Video6_3_Joining_Data_With_Query_Syntax");
Console.WriteLine("-------------------------------------");
Console.WriteLine("");
var cars = ProcessDataFromFiles.ProcessCar("fuel.csv");
var manufactuers = ProcessDataFromFiles.ProcessManufacturers("manufacturers.csv");
// Query Syntax herunder
var queryQuerySyntax =
from car in cars
join manufacturer in manufactuers on
car.Manufacturer equals manufacturer.Name
orderby car.Combined descending, car.Name ascending
select new
{
manufacturer.Headquarters,
car.Name,
car.Combined
};
foreach (var car in queryQuerySyntax.Take(10))
{
Console.WriteLine($"{car.Headquarters} : {car.Name} : {car.Combined}");
}
}
public static void Video6_5_Creating_A_Join_With_A_Composition_Start()
{
Console.WriteLine("");
Console.WriteLine("Video6_5_Creating_A_Join_With_A_Composition");
Console.WriteLine("-----------------------------------------");
Console.WriteLine("");
var cars = ProcessDataFromFiles.ProcessCar("fuel.csv");
var manufacturers = ProcessDataFromFiles.ProcessManufacturers("manufacturers.csv");
// Query Syntax herunder
// Når vi bruger Query Syntax, er der en "tradition" for, at vi
// bestræber os på at gøre tingene så læsbare, som vi kan. Det kan
// ses herunder, hvor vi bruger navnene car og manufacurer. Ví kunne
// have valgt at bruge én bogstavs navne som f.eks. c (i stedet for car)
// og m (i stedet for manufacturer).
// Når vi bruger Extension Method Syntax er der omvendt en "´tradition" for,
// at vi anvender én bogstavs navne, når vi kommer omkring Lambda Expressions
// og vi skal navngive/specificere indkommende parametre til Lambda
// Expressions. Dette kan vi se, når vi kommer til Extension Method Syntax
// i det efterfølgende.
// I de foregående eksempler har der været brugt både
// én bogstavs navne og mere sigende og længere navne, når vi har brugt
// navngivning for Lambda Expression indkommende prrametre i forbindelse
// med Extension Method Syntax.
var queryQuerySyntax =
from car in cars
join manufacturer in manufacturers on
new { car.Manufacturer, car.Year }
equals
new { Manufacturer = manufacturer.Name, manufacturer.Year }
// Navnet skal være det samme i Car.Manufacturer og manufacturer.name
// Derfor er det nødvendig med sætningen : Manufacturer = manufacturer.Name !!!
orderby car.Combined descending, car.Name ascending
select new
{
manufacturer.Headquarters,
car.Name,
car.Combined
};
Console.WriteLine("Query Syntax");
Console.WriteLine("");
foreach (var car in queryQuerySyntax.Take(10))
{
Console.WriteLine($"{car.Headquarters} : {car.Name} : {car.Combined}");
}
Console.WriteLine("");
Console.WriteLine("Extension Method Syntax");
Console.WriteLine("");
// Extension Method Syntax herunder.
// Som nævnt tidligere i dette dokument, bruger vi her én bogstavs
// navngivning for indkommende Lambda Expression parametre i
// forbindelse med Extension Method Syntax. Og i alle efterfølgende
// eksmepler vil denne én bogstavs navngivning blive anvendt.
// I forbindelse med denne én bogstavs navngivning har jeg valgt at
// benytte første bogstav i det navn, som vi forkorter efter.
// Det vil sige c for for car og m for manufacturer og så fremdeles.
// Denne navgivnings konvention er også den, der gennrelt amvendes,
// nåt vi snakker om Lambda Expression og indkommende parametre.
// efterfølgende Lambda Expressions
var queryMethodSyntax =
cars.Join(manufacturers,
c => new { c.Manufacturer, c.Year },
m => new { Manufacturer = m.Name, m.Year },
// Navnet skal være det samme i C.Manufacturer og m.name
// Derfor er det nødvendig med sætningen : Manufacturer = m.Name !!!
(c, m) => new
{
m.Headquarters,
c.Name,
c.Combined
})
.OrderByDescending(c => c.Combined)
.ThenBy(c => c.Name);
foreach (var car in queryMethodSyntax.Take(10))
{
Console.WriteLine($"{car.Headquarters} : {car.Name} : {car.Combined}");
}
}
public static void Video6_4_Joining_Data_Using_Extension_Method_Syntax_Start()
{
Console.WriteLine("");
Console.WriteLine("Video6_4_Joining_Data_Using_Extension_Method_Syntax");
Console.WriteLine("------------------------------------------------");
Console.WriteLine("");
var cars = ProcessDataFromFiles.ProcessCar("fuel.csv");
var manufacturers = ProcessDataFromFiles.ProcessManufacturers("manufacturers.csv");
// Extension Method Syntax herunder
// Navngivningen i eksemplet herunder er den man tiest støder på, når man
// arbejder med Lambda Expression.
// Ved alle indkommende parametre til et Lambda Expression benytter man
// sig af én bogstavs notation. For at gøre det lettere at læse koden
// benytter man ofte af et bogstav, der er første bogtsva i det, man
// arbejder med. F.eks c for car og m for manufacturer.
var queryMethodSyntaxSingleLetterNaming =
cars.Join(manufacturers,
c => c.Manufacturer,
m => m.Name, (c, m) => new
{
m.Headquarters,
c.Name,
c.Combined
}) // Her bliver de 2 objekter cars og manufacturers samlet i ét objekt
.OrderByDescending(c => c.Combined)
.ThenBy(c => c.Name);
foreach (var car in queryMethodSyntaxSingleLetterNaming.Take(10))
{
Console.WriteLine($"{car.Headquarters} : {car.Name} : {car.Combined}");
}
Console.WriteLine("");
// Navngivningen i eksemplet herunder støder man ikke på så tit, når man
// arbejder med Lambda Expression. Men den er måske lettere at læse
// end én bogstavs navngivningen fra eksemplet herover.
// Som altid indefor progtrammeringens verden er det et spørgsmål
// om smag og behag. Og der er ikke noget, der er mere rigtigt end andet.
var queryMethodSyntaxMoreReadableNaming =
cars.Join(manufacturers,
car => car.Manufacturer,
manufacturer => manufacturer.Name, (car, manufacturer) => new
{
manufacturer.Headquarters,
car.Name,
car.Combined
}) // Her bliver de 2 objekter cars og manufacturers samlet i ét objekt
.OrderByDescending(car => car.Combined)
.ThenBy(car => car.Name);
foreach (var car in queryMethodSyntaxMoreReadableNaming.Take(10))
{
Console.WriteLine($"{car.Headquarters} : {car.Name} : {car.Combined}");
}
Console.WriteLine("");
var queryMethodSyntax1 =
cars.Join(manufacturers,
c => c.Manufacturer,
m => m.Name, (c, m) => new
{
Car = c,
Manufacturer = m
})
.OrderByDescending(c => c.Car.Combined)
.ThenBy(c => c.Car.Name);
foreach (var car in queryMethodSyntax1.Take(10))
{
Console.WriteLine($"{car.Manufacturer.Headquarters} : {car.Car.Manufacturer} : {car.Car.Name} : {car.Car.Combined}");
}
Console.WriteLine("");
var queryMethodSyntax2 =
cars.Join(manufacturers,
c => c.Manufacturer,
m => m.Name, (c, m) => new
{
Car = c,
Manufacturer = m
})
.OrderByDescending(c => c.Car.Combined)
.ThenBy(c => c.Car.Name)
.Select(c => new
{
c.Manufacturer.Headquarters,
c.Car.Name,
c.Car.Combined
});
foreach (var car in queryMethodSyntax1.Take(10))
{
Console.WriteLine($"{car.Manufacturer.Headquarters} : {car.Car.Name} : {car.Car.Combined}");
}
// Der kan ikke bruges Include her, som når vi anvender EntityFramework
// op imod f.eks. en database.
// Så Include, ThenInclude o.s.ver altså funktionalitet, som Entity
// Framework bygger ovenpå Linq.
}
public static void Video6_9_Aggreating_Data_Start()
{
Console.WriteLine("");
Console.WriteLine("Video6_9_Aggreating_Data");
Console.WriteLine("----------------------");
Console.WriteLine("");
var cars = ProcessDataFromFiles.ProcessCar("fuel.csv");
var manufacturers = ProcessDataFromFiles.ProcessManufacturers("manufacturers.csv");
// Query Syntax herunder
var queryQuerySyntax =
from car in cars
group car by car.Manufacturer into carGroup
select new
{
// Vi laver en projektion her.
Name = carGroup.Key,
Max = carGroup.Max(c => c.Combined),
Min = carGroup.Min(c => c.Combined),
Avg = carGroup.Average(c => c.Combined),
NumberOfCars = carGroup.Count()
};
Console.WriteLine("Query Syntax");
Console.WriteLine("");
foreach (var result in queryQuerySyntax)
{
Console.WriteLine($"{result.Name} : ");
Console.WriteLine($"\t Antal {result.Name} biler : {result.NumberOfCars}");
Console.WriteLine($"\t Max : {result.Max}");
Console.WriteLine($"\t Min : {result.Min}");
Console.WriteLine($"\t Avg : {result.Avg}");
Console.WriteLine("");
}
var queryQuerySyntaxOrdered =
from car in cars
group car by car.Manufacturer into carGroup
select new
{
// Vi laver en projektion her.
Name = carGroup.Key,
Max = carGroup.Max(c => c.Combined),
Min = carGroup.Min(c => c.Combined),
Avg = carGroup.Average(c => c.Combined),
NumberOfCars = carGroup.Count()
} into result
orderby result.Max descending
select result;
Console.WriteLine("");
Console.WriteLine("Ordered by most fuel efficient car");
Console.WriteLine("");
foreach (var result in queryQuerySyntaxOrdered)
{
Console.WriteLine($"{result.Name} : ");
Console.WriteLine($"\t Antal {result.Name} biler : {result.NumberOfCars}");
Console.WriteLine($"\t Max : {result.Max}");
Console.WriteLine($"\t Min : {result.Min}");
Console.WriteLine($"\t Avg : {result.Avg}");
Console.WriteLine("");
}
}
public static void Video6_8_Challenge_Answer_Group_By_Country_start()
{
Console.WriteLine("");
Console.WriteLine("Video6_8_Challenge_Answer_Group_By_Country");
Console.WriteLine("----------------------------------------");
Console.WriteLine("");
Console.WriteLine("Nu sorteres efter land og derefter efter 3 mest brændstof økonomiske biler pr land");
Console.WriteLine("");
Console.WriteLine("Der anvendes joining - ordering - grouping - flattening => (SelectMany)");
Console.WriteLine("");
var cars = ProcessDataFromFiles.ProcessCar("fuel.csv");
var manufacturers = ProcessDataFromFiles.ProcessManufacturers("manufacturers.csv");
// Query Syntax herunder
Console.WriteLine("");
Console.WriteLine("Query Syntax");
Console.WriteLine("");
var queryQuerySyntax =
from manufacturer in manufacturers
join car in cars on manufacturer.Name equals car.Manufacturer
into carGroup
select new
{
Manufacturer = manufacturer,
Cars = carGroup
} into result
orderby result.Manufacturer.Headquarters
group result by result.Manufacturer.Headquarters;
foreach (var group in queryQuerySyntax)
{
Console.WriteLine($"{group.Key} : ");
foreach (var car in group.SelectMany(g => g.Cars).
OrderByDescending(c => c.Combined).
Take(3))
{
Console.WriteLine($"\t{car.Manufacturer} : {car.Name} : {car.Combined}");
}
Console.WriteLine("");
}
// Extension Method Syntax herunder.
Console.WriteLine("");
Console.WriteLine("Extension Method Syntax");
Console.WriteLine("");
var queryMethodSyntax =
manufacturers.GroupJoin(cars, m => m.Name, c => c.Manufacturer,
(m, g) =>
new
{
Manufacturer = m,
Cars = g
})
.OrderBy(m => m.Manufacturer.Headquarters)
.GroupBy(m => m.Manufacturer.Headquarters);
foreach (var group in queryMethodSyntax)
{
Console.WriteLine($"{group.Key} : ");
foreach (var car in group.SelectMany(g => g.Cars).
OrderByDescending(c => c.Combined).
Take(3))
{
Console.WriteLine($"\t{car.Manufacturer} : {car.Name} : {car.Combined}");
}
Console.WriteLine("");
}
}
public static void Video6_10_Efficient_Aggregation_With_Extended_Method_Start()
{
Console.WriteLine("");
Console.WriteLine("Video6_10_Efficient_Aggregation_With_Extended_Method");
Console.WriteLine("----------------------");
Console.WriteLine("");
var cars = ProcessDataFromFiles.ProcessCar("fuel.csv");
var manufacturers = ProcessDataFromFiles.ProcessManufacturers("manufacturers.csv");
// Extension Method Syntax herunder.
Console.WriteLine("Extension Method Syntax");
Console.WriteLine("");
Console.WriteLine("");
var queryMethodSyntaxOwnFunction_Static =
cars.GroupBy(c => c.Manufacturer)
.Select(g =>
{
var results = CarStatistics.CalculateCarsStatistics_Static(g);
return(new
{
Name = g.Key,
Max = results.Max,
Min = results.Min,
Avg = results.Average,
NumberOfCars = results.NumberOfCars
});
})
.OrderByDescending(r => r.Max);
Console.WriteLine("Udskrift fra queryMethodSyntaxOwnFunction_Static");
Console.WriteLine("");
foreach (var result in queryMethodSyntaxOwnFunction_Static)
{
Console.WriteLine($"{result.Name} : ");
Console.WriteLine($"\t Antal {result.Name} biler : {result.NumberOfCars}");
Console.WriteLine($"\t Max : {result.Max}");
Console.WriteLine($"\t Min : {result.Min}");
Console.WriteLine($"\t Avg : {result.Avg}");
Console.WriteLine("");
}
Console.WriteLine("");
Console.WriteLine("");
var queryMethodSyntaxOwnFunction_Object =
cars.GroupBy(c => c.Manufacturer)
.Select(g =>
{
CarStatistics carStatistics_Object = new CarStatistics();
var results = carStatistics_Object.CalculateCarsStatistics_Object(g);
return(new
{
Name = g.Key,
Max = results.Max,
Min = results.Min,
Avg = results.Average,
NumberOfCars = results.NumberOfCars
});
})
.OrderByDescending(r => r.Max);
Console.WriteLine("Udskrift fra queryMethodSyntaxOwnFunction_Object");
Console.WriteLine("");
foreach (var result in queryMethodSyntaxOwnFunction_Object)
{
Console.WriteLine($"{result.Name} : ");
Console.WriteLine($"\t Antal {result.Name} biler : {result.NumberOfCars}");
Console.WriteLine($"\t Max : {result.Max}");
Console.WriteLine($"\t Min : {result.Min}");
Console.WriteLine($"\t Avg : {result.Avg}");
Console.WriteLine("");
}
Console.WriteLine("");
Console.WriteLine("");
var queryMethodSyntaxOwnFunction_ExtensionMethod =
cars.GroupBy(c => c.Manufacturer)
.Select(g =>
{
var results = g.CalculateCarsStatistics();
return(new
{
Name = g.Key,
Max = results.Max,
Min = results.Min,
Avg = results.Average,
NumberOfCars = results.NumberOfCars
});
})
.OrderByDescending(r => r.Max);
Console.WriteLine("Udskrift fra queryMethodSyntaxOwnFunction_Static");
Console.WriteLine("");
foreach (var result in queryMethodSyntaxOwnFunction_ExtensionMethod)
{
Console.WriteLine($"{result.Name} : ");
Console.WriteLine($"\t Antal {result.Name} biler : {result.NumberOfCars}");
Console.WriteLine($"\t Max : {result.Max}");
Console.WriteLine($"\t Min : {result.Min}");
Console.WriteLine($"\t Avg : {result.Avg}");
Console.WriteLine("");
}
Console.WriteLine("");
Console.WriteLine("");
var queryMethodSyntax_From_Scott_Allen_PLuralsight_Video =
cars.GroupBy(c => c.Manufacturer)
.Select(g =>
{
var results = g.Aggregate(new CarStatistics(),
(acc, c) => acc.Accumulate(c),
acc => acc.Compute());
return(new
{
Name = g.Key,
Max = results.Max,
Min = results.Min,
Avg = results.Average,
NumberOfCars = results.NumberOfCars
});
})
.OrderByDescending(r => r.Max);
// Ved at bruge syntaksen/ metoden herover undgår vi at skulle
// løbe igennem alle Cars 3 gange for at finde henholdsvis Max, Min
// og Average værdier.
Console.WriteLine("Udskrift fra queryMethodSyntax_From_Scott_Allen_PLuralsight_Video");
Console.WriteLine("");
foreach (var result in queryMethodSyntax_From_Scott_Allen_PLuralsight_Video)
{
Console.WriteLine($"{result.Name} : ");
Console.WriteLine($"\t Antal {result.Name} biler : {result.NumberOfCars}");
Console.WriteLine($"\t Max : {result.Max}");
Console.WriteLine($"\t Min : {result.Min}");
Console.WriteLine($"\t Avg : {result.Avg}");
Console.WriteLine("");
}
}
public static void Video6_6_Grouping_Data_Start()
{
Console.WriteLine("");
Console.WriteLine("Video6_6_Grouping_Data");
Console.WriteLine("--------------------");
Console.WriteLine("");
var cars = ProcessDataFromFiles.ProcessCar("fuel.csv");
var manufacturers = ProcessDataFromFiles.ProcessManufacturers("manufacturers.csv");
// Query Syntax herunder
var queryQuerySyntax =
from car in cars
group car by car.Manufacturer;
Console.WriteLine("Query Syntax");
Console.WriteLine("");
foreach (var group in queryQuerySyntax)
{
Console.WriteLine($"{group.Key}har {group.Count()} cars");
// group by giver et Key felt !!!
}
Console.WriteLine("");
foreach (var group in queryQuerySyntax)
{
Console.WriteLine(group.Key);
foreach (var car in group.OrderByDescending(c => c.Combined).Take(2))
{
Console.WriteLine($"\t{car.Name} : {car.Combined}");
}
Console.WriteLine("");
}
var queryQuerySyntax1 =
from car in cars
group car by car.Manufacturer.ToUpper() into manufacturer
orderby manufacturer.Key
select manufacturer;
Console.WriteLine("");
foreach (var group in queryQuerySyntax1)
{
Console.WriteLine(group.Key);
foreach (var car in group.OrderByDescending(c => c.Combined).Take(2))
{
Console.WriteLine($"\t{car.Name} : {car.Combined}");
}
Console.WriteLine("");
}
// Extension Method Syntax herunder.
Console.WriteLine("");
Console.WriteLine("Extension Method Syntax");
Console.WriteLine("");
var queryMethodSyntax =
cars.GroupBy(c => c.Manufacturer.ToUpper())
.OrderBy(g => g.Key)
.Select(c => c);
// Som sædvanlig ikke nødvendig med .Select for et Expresion Method
// Syntax udtryk. Men man kan tage det med, hvis man synes.
foreach (var group in queryMethodSyntax)
{
Console.WriteLine(group.Key);
foreach (var car in group.OrderByDescending(c => c.Combined).Take(2))
{
Console.WriteLine($"\t{car.Name} : {car.Combined}");
}
Console.WriteLine("");
}
}
public static void Video6_7_Using_A_GroupJoin_For_Hierarchy_Start()
{
Console.WriteLine("");
Console.WriteLine("Video6_7_Using_A_GroupJoin_For_Hierarchy");
Console.WriteLine("--------------------------------------");
Console.WriteLine("");
Console.WriteLine("Nu lande informationer med for Headquarters");
Console.WriteLine("");
var cars = ProcessDataFromFiles.ProcessCar("fuel.csv");
var manufacturers = ProcessDataFromFiles.ProcessManufacturers("manufacturers.csv");
// Query Syntax herunder
var queryQuerySyntax =
from manufacturer in manufacturers
join car in cars on manufacturer.Name equals car.Manufacturer
into carGroup
orderby manufacturer.Name
select new
{
Manufacturer = manufacturer,
Cars = carGroup
};
Console.WriteLine("Query Syntax");
Console.WriteLine("");
foreach (var group in queryQuerySyntax)
{
Console.WriteLine($"{group.Manufacturer.Name} : {group.Manufacturer.Headquarters}");
foreach (var car in group.Cars.OrderByDescending(c => c.Combined).Take(2))
{
Console.WriteLine($"\t{car.Name} : {car.Combined}");
}
Console.WriteLine("");
}
// Extension Method Syntax herunder.
Console.WriteLine("");
Console.WriteLine("Extension Method Syntax");
Console.WriteLine("");
var queryMethodSyntax =
manufacturers.GroupJoin(cars, m => m.Name, c => c.Manufacturer,
(m, g) =>
new
{
Manufacturer = m,
Cars = g
})
.OrderBy(m => m.Manufacturer.Name);
foreach (var group in queryMethodSyntax)
{
Console.WriteLine($"{group.Manufacturer.Name} : {group.Manufacturer.Headquarters}");
foreach (var car in group.Cars.OrderByDescending(c => c.Combined).Take(2))
{
Console.WriteLine($"\t{car.Name} : {car.Combined}");
}
Console.WriteLine("");
}
}