Question

我有两个SQLite表t1和t2，它们具有相同的字段：name，value1，value2，value3。

至关重要的是，（a）表t1仅包含单个记录John|20|19|4，而（b）该记录可能会更改。

我想从T2中选择所有那些记录，其中t2.value1 <= t1.value1（即，唯一记录中的单个t1.value1）和t2.value2 <= t1.value2和t3.value3。这可能吗？

Answer 1

这应该做到：

select *
from T2
where exists 
    ( select * 
      from T1 
      where T2.Value1 <= T1.Value1 and 
            T2.Value2 <= T1.Value2 and 
            T2.Value3 <= T1.Value3
     )

Answer 2

是的，有可能。您可以尝试以下查询

WITH (SELECT TOP(1) FROM table t1 AS record),
SELECT * FROM table t2 WHERE t2.value1 <= record.value1 AND t2.value2 <= 
record.value2 AND t3.value3 <= record.value3;

通过将字段与单个其他记录进行比较来选择一个表中的记录

2 个答案: