Question

我有一张桌子＆＃34; typl＆＃34;仅包含2个值：

typl 
------
 COL
 IND

和表＆＃34;存储＆＃34;有2列：

achl | typl 
------+------
 AAAA | IND
 AAAA | IND
 AAAA | IND
 AAAA | IND
 AAAA | IND
 AAAA | IND
 BBBB | COL
 BBBB | COL
 BBBB | IND
 BBBB | IND
 BBBB | IND
 BBBB | IND
 BBBB | IND
 BBBB | IND
 BBBB | IND

问题：我可以找到一个查询，对于商店表格中的一组achl，如果只有一个类似于achl =＆＃39; AAAA＆＃39;，那么所有行都将是交叉加入＆＃34; typl＆＃34;表，所以结果将是：

achl | typl 
------+------
 AAAA | COL
 AAAA | COL
 AAAA | COL
 AAAA | COL
 AAAA | COL
 AAAA | COL
 AAAA | IND
 AAAA | IND
 AAAA | IND
 AAAA | IND
 AAAA | IND
 AAAA | IND
 BBBB | COL
 BBBB | COL
 BBBB | IND
 BBBB | IND
 BBBB | IND
 BBBB | IND
 BBBB | IND
 BBBB | IND
 BBBB | IND

Answer 1

SELECT 
    * 
FROM store 
WHERE achl IN (
    SELECT achl 
    FROM store
    GROUP BY achl
    HAVING COUNT(DISTINCT typl) = 1
)

Answer 2

SQL Fiddle

select *
from (
    select achl, typl
    from store
    union all
    select achl, t.typl
    from store s cross join typl t
    where (achl, t.typl) not in (
        select achl, typl
        from store
    )
) s
order by achl, typl

一个正确加入的交叉联接

2 个答案: