1
我有三個表,這裏用對象表示並轉換成SQLite表。 CategoryGroup
表有多個Categories
,每個Category
有多個Phrases
。我如何做一個多表SQL的SQL Server連接
public class CategoryGroup
{
[PrimaryKey, NotNull]
public int Id { get; set; }
public string Name { get; set; }
public bool Selected { get; set; }
}
public class Category : ICategory
{
[PrimaryKey, NotNull]
public int Id { get; set; }
public int CategoryGroupId { get; set; }
public string Name { get; set; }
public bool Selected { get; set; }
}
public class Phrase : IPhrase
{
public int CategoryId { get; set; }
[PrimaryKey, NotNull]
public string PhraseId { get; set; }
public string English { get; set; }
public string Romaji { get; set; }
public string Kana { get; set; }
public string Kanji { get; set; }
public int Modified { get; set; }
}
我想這樣做是CategoryGroup加入這三個表,並將它們組合,然後在選定的盤點報告。
我創建了這個SQL,但我不確定三個表連接。
SELECT CG.Id, CG.Name, COUNT(*) AS PhraseCount
FROM CategoryGroup AS CG
FROM Category AS C
JOIN CG.Id = P.CategoryId
JOIN Phrase AS P ON C.Id = P.CategoryId
GROUP BY CG.Id
ORDER BY CG.Name
有人可以給我建議,我怎麼可以做的加入?