Question

我需要检索与6号或7号球员在同一街道和城镇居住的所有玩家的玩家编号，名称，街道和城镇;

我不确定如何编写SQL查询，我想我需要在WHERE子句中有一个子查询但是无法弄清楚如何执行它。

这是我提出的，但我现在无法测试它

SELECT playerNo, name, street, town
FROM Players
WHERE street IN ( SELECT street, playerNo
                  FROM Players
                  WHERE playerNo IN (6,7));
AND town IN (SELECT town, playerNo
             FROM Players
             WHERE playerNo IN (6,7));

应与Oracle 10g兼容

感谢所有回复的人！

Answer 1

您没有说明您的DBMS，因此这是ANSI SQL解决方案（适用于Oracle，PostgreSQL，DB2，Teradata，MySQL以及其他许多人）：

SELECT playerNo, name, street, town
FROM Players
WHERE (street, town) IN (SELECT street, town
                         FROM Players
                         WHERE playerNo IN (6,7));

关于IN运营商的附注：

您的表达式town IN (SELECT town, playerNO ...无效，因为子选择必须与IN运算符左侧的列完全相同。在您的情况下，您必须写town IN (SELECT town FROM ...)

Answer 2

这样的事情可以解决问题：

select t.playerNumber, t.name, t.street, t.town
from tablename t
inner join (select street, town from tablename where playerNumber in (6,7)) aux on aux.street = t.street and aux.town = t.town

Answer 3

SELECT p1.playerNo, p1.name, p1.street, p1.town
FROM Players AS p1
INNER JOIN Players AS p2 ON p2.street = p1.street AND p2.town = p1.town
WHERE p2.playerNo IN (6,7)

通常最好避免使用子查询，因为数据库优化器无法“看到内部”。

带有子查询的SQL查询

3 个答案: