我有一個類似于以下格式的表格：id | name | year | Quality| Location |------------------------------------------1 | Apple | year1 | Good | Asia |2 | Apple | year2 | Better | Asia |3 | Apple | year3 | Best | Asia |4 | Apple | year1 | Best | Africa |5 | Apple | year2 | Bad | Africa |6 | Apple | year3 | Better | Africa |7 | Apple | year1 | Best | Europe |8 | Apple | year2 | Bad | Europe |9 | Apple | year3 | Better | Europe |10 | Orange | year1 | Bad | Asia |11 | Orange | year2 | Better | Asia |12 | Orange | year3 | Bad | Asia | 13 | Orange | year1 | Best | Africa |14 | Orange | year2 | Better | Africa |15 | Orange | year3 | Bad | Africa |16 | Orange | year1 | Best | Europe |17 | Orange | year2 | Better | Europe |18 | Orange | year3 | Best | Europe |19 | Mango | year1 | Bad | Asia |20 | Mango | year2 | Better | Asia |21 | Mango | year3 | Better | Asia |22 | Mango | year1 | Good | Africa |23 | Mango | year2 | Better | Africa |24 | Mango | year3 | Good | Africa |25 | Mango | year1 | Best | Europe |26 | Mango | year2 | Better | Europe |27 | Mango | year3 | Best | Europe |我需要 LINQ 中這種格式的列表：{ Location: Asia, year: year1, Good: 1, Bad: 2, Better: 0, Best: 0 }{ Location: Asia, year: year2, Good: 0, Bad: 0, Better: 3, Best: 0 }{ Location: Asia, year: year3, Good: 0, Bad: 1, Better: 1, Best: 1 }....我的 LINQ 查詢是這樣的：var result = context.Fruits .Groupby(f => new { f.Year,f.Location,f.Quality }) .Select(g => new { Year = g.Key.Year, Location = g.Key.Location, Quality = g.Key.Quality, Count = g.Count() });如何使用 LINQ 獲得所需的格式？我是否必須得到結(jié)果，然后使用 for each 來得到我需要的格式？
1 回答
斯蒂芬大帝
TA貢獻1827條經(jīng)驗 獲得超8個贊
您想要Count()該Quality屬性，因此將其用作分組中的鍵確實有意義。如果您只是省略它并僅按年份和位置分組，您將獲得所需的輸出。
public class Program
{
public static void Main()
{
var fruits = new List<Fruit> {
new Fruit { Id = 1, Name = "Apple", Year = "year1", Quality = "Good", Location ="Asia"},
new Fruit { Id = 2, Name = "Apple", Year = "year2", Quality = "Better", Location ="Asia"},
new Fruit { Id = 3, Name = "Apple", Year = "year3", Quality = "Better", Location ="Asia"},
new Fruit { Id = 4, Name = "Apple", Year = "year1", Quality = "Best", Location ="Africa"},
new Fruit { Id = 5, Name = "Orange", Year = "year1", Quality = "Vad", Location ="Asia"},
new Fruit { Id = 6, Name = "Orange", Year = "year2", Quality = "Better", Location ="Asia"},
new Fruit { Id = 7, Name = "Orange", Year = "year3", Quality = "Bad", Location ="Asia"},
};
var result = fruits.GroupBy(f => new { f.Year,f.Location})
.Select(g => new
{
Year = g.Key.Year,
Location = g.Key.Location,
Good = g.Count(x => x.Quality == "Good"),
Better = g.Count(x => x.Quality == "Better"),
Best = g.Count(x => x.Quality == "Best"),
});
foreach(var line in result) {
Console.WriteLine(String.Format("Year: {0} - Location: {1} - Good: {2} - Better: {3} - Best: {4}", line.Year, line.Location, line.Good, line.Better, line.Best));
}
}
}
public class Fruit
{
public int Id { get; set; }
public string Name { get; set; }
public string Year { get; set; }
public string Quality { get; set; }
public string Location { get; set; }
}
輸出：
Year: year1 - Location: Asia - Good: 1 - Better: 0 - Best: 0
Year: year2 - Location: Asia - Good: 0 - Better: 2 - Best: 0
Year: year3 - Location: Asia - Good: 0 - Better: 1 - Best: 0
Year: year1 - Location: Africa - Good: 0 - Better: 0 - Best: 1
小提琴：https ://dotnetfiddle.net/eg99at
- 1 回答
- 0 關(guān)注
- 158 瀏覽
添加回答
舉報
0/150
提交
取消