带有 RIGHT JOIN 的 CROSS JOIN

Question

我有一个 table "typl" 只包含 2 个值：

typl 
------
 COL
 IND

和一个 table "store" 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，对于商店中的一组 achl table，如果只有一个 typl，比如 achl='AAAA'，所有的行都会交叉加入 "typl" table，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

带有 RIGHT JOIN 的 CROSS JOIN

A CROSS JOIN with a RIGHT JOIN

postgresql

join

cross-join