獲取GROUP BY的第一個條件作爲附加行嗎？

Question

我的sql字符串如下;

SELECT 
      Country, 
      City, 
      COUNT(*) AS [Count] 
     FROM 
      CountiresAndCities 
     GROUP BY 
      Country, 
      City 

我想獲得國家的價值太多，因爲額外的行不使用UNION是可能的嗎？

謝謝你的忠告。

Answer 1

您可以使用GROUPING SETS這個

SELECT Country, 
     City, 
     COUNT(*) AS [Count] 
FROM CountiresAndCities 
GROUP BY grouping sets ((Country, City), (Country)) 
ORDER BY grouping(City), 
      Country, 
      City 

SQL Fiddle

Answer 2

，我想出了是使用一個子查詢來計算國家和最簡單的辦法：

例子（使用SQLite的）：

CREATE TABLE Games (Country TEXT, City TEXT); 
INSERT INTO Games VALUES ('USA', 'New York'); 
INSERT INTO Games VALUES ('USA', 'New York'); 
INSERT INTO Games VALUES ('USA', 'New York'); 
INSERT INTO Games VALUES ('USA', 'Los Angeles'); 
INSERT INTO Games VALUES ('USA', 'Los Angeles'); 
INSERT INTO Games VALUES ('USA', 'San Francisco'); 
INSERT INTO Games VALUES ('USA', 'San Francisco'); 
INSERT INTO Games VALUES ('France', 'Paris'); 
INSERT INTO Games VALUES ('France', 'Paris'); 
INSERT INTO Games VALUES ('France', 'Paris'); 
INSERT INTO Games VALUES ('France', 'Paris'); 
INSERT INTO Games VALUES ('Spain', 'Madrid'); 
INSERT INTO Games VALUES ('Spain', 'Madrid'); 
INSERT INTO Games VALUES ('Spain', 'Barcelona'); 
.headers on 
.mode column 
SELECT Country, City, MIN(CountryCount) AS CountryCount, COUNT(*) AS CityCount 
FROM CountiresAndCities JOIN (
    SELECT Country, COUNT(*) AS CountryCount 
    FROM CountiresAndCities GROUP BY Country 
) USING (Country) 
GROUP BY Country, City; 

Country  City  CountryCount CityCount 
---------- ---------- ------------ ---------- 
France  Paris  4    4   
Spain  Barcelona 3    1   
Spain  Madrid  3    2   
USA   Los Angele 7    2   
USA   New York 7    3   
USA   San Franci 7    2