Question

我想要一个SELECT查询，它可以获得user1＆amp;的8个特定组合。 user2（用户2和用户1的组合也值得拥有而不是多余的）。 “IN”声明似乎值得。

直接相关的问题。 1.“WHERE IN”语句可以嵌套吗？

如果没有，我可以如何最有效/最容易地构建查询，以便我可以指定（对于4对，其中user1和user2切换位置 - 8种组合）：(where user1 = billy AND user2 = sue) OR (where user1 = sue AND user2 =billy) OR (user1 = jack AND user2 = jill) OR (user1 = jill AND user2 = jack) ...等？

[此时运行查询并查看相关信息似乎更容易。]

当前的想法：

sqlite3 -header -separator , some.db "SELECT DISTINCT programquality.time, simscores.user1, simscores.user2, simscores.simscore, programquality.gf, programquality.ga, programquality.pq FROM simscores LEFT JOIN programquality ON programquality.time = simscores.time AND programquality.username = simscores.user1 WHERE programquality.pq IS NOT NULL WHERE simscores.user1 IN ("abraham","billy","carl","dave","ethan","frank","george","harry") WHERE simscores.user2 IN ("abraham","billy","carl","dave","ethan","frank","george","harry");"

我已经使用了这个，但显示了一些不相关的数据。

sqlite3 -header -separator , some.db 'SELECT DISTINCT programquality.time, simscores.user1, simscores.user2, simscores.simscore, programquality.gf, programquality.ga, programquality.pq FROM simscores LEFT JOIN programquality ON programquality.time = simscores.time AND programquality.username = simscores.user1 WHERE (simscores.user1  = "billy" OR simscores.user1 = "suzy" OR simscores.user1 = "john") AND (simscores.user2  = "billy" OR simscores.user2 = "suzy" OR simscores.user2 = "john") AND programquality.pq IS NOT NULL AND programquality.time IS NOT NULL;'

Answer 1

查询can have only one WHERE clause，但该表达式可以将多个条件与AND或OR结合使用：

SELECT ...
FROM ...
WHERE programquality.pq IS NOT NULL AND
      simscores.user1 IN ('abraham', 'billy', ...) AND
      simscores.user2 IN ('abraham', 'billy', ...)

但是，这些IN表达式不允许您匹配user1和user2的特定值。你无法避免列出你想要的所有组合。

但是，您可以通过检查有效组合的组合名称来稍微简化表达式：

... WHERE ... AND
          simscores.user1 || '+' || simscores.user2
           IN ('billy+sue', 'sue+billy',
               'jack+jill', 'jill+jack',
               ...)

嵌套“WHERE IN”（或AND，OR语句）SQLite

1 个答案: