两个表
Table: Ships
| name | yearLaunched | country | numGuns | gunSize | displacement |
| Bismarck | 1940 | Germany | 8 | 15 | 42000 |
| Oktyabrskaya Revolutsia | 1914 | USSR | 12 | 12 | 23000 |
| Warspite | 1915 | Great Britain | 8 | 15 | 31000 |
| Hood | 1920 | Great Britain | 8 | 15 | 41000 |
| Nelson | 1927 | Great Britain | 9 | 16 | 34000 |
| Prince of Wales | 1941 | Great Britain | 10 | 14 | 38000 |
| Giulio Cesare | 1914 | Italy | 10 | 13 | 24000 |
| Texas | 1914 | USA | 10 | 14 | 27000 |
| Arizona | 1916 | USA | 12 | 14 | 33000 |
| California | 1921 | USA | 12 | 14 | 32000 |
| West Virginia | 1923 | USA | 8 | 16 | 32000 |
| New Jersey | 1943 | USA | 9 | 16 | 46000 |
| Missouri | 1944 | USA | 9 | 16 | 46000 |
| Kirishima | 1915 | Japan | 8 | 14 | 32000 |
| Fuso | 1915 | Japan | 12 | 14 | 35000 |
| Yamashiro | 1917 | Japan | 12 | 14 | 35000 |
| Nagato | 1920 | Japan | 8 | 16 | 38000 |
| Yamato | 1941 | Japan | 9 | 18 | 65000 |
| Musashi | 1942 | Japan | 9 | 18 | 65000 |
Table: Battles
| ship | battleName | result |
| Fuso | Surigao Strait | sunk |
| Yamashiro | Surigao Strait | sunk |
| California | Surigao Strait | ok |
| West Virginia | Surigao Strait | ok |
| Bismarck | North Atlantic | sunk |
| Hood | North Atlantic | sunk |
| Prince of Wales | North Atlantic | damaged |
其中ships.name=battles,ship
我用
select distinct ships.country ,Battles.battleName,ships.country from ships right join Battles on ships.name=Battles.ship
查出下面结果
| country | battleName | country |
| Japan | Surigao Strait | Japan |
| USA | Surigao Strait | USA |
| Germany | North Atlantic | Germany |
| Great Britain | North Atlantic | Great Britain |
正确答案是
| country | country |
| Japan | USA |
| Germany | Great Britain |
请问怎么查？（就是查具有同一battleName的country）
还有
我用
select country,count(*)as numsunk
from ships join Battles on ships.name=Battles.ship
where battleName='Surigao Strait'
and result='sunk'
group by country
查出
| country | numsunk |
| Japan | 2 |
但正确答案是
| country | numSunk |
| Japan | 2 |
| USA | 0 |
怎么解决谢谢
虽然不干.NET事，请不要怪，百度了N天没结果