Question

如果我想找到只有单个ruleid为2的联系人，需要有关sql的帮助。因此输出应该是联系人ID 1和7。我不是在寻找联系人ID 5＆amp; 6在输出中，因为它们有多个规则，即使它们有规则2

Contactid   ruleid
1                   2
5                   3
5                   2
6                   4
6                   2
7                   2

有人可以帮忙解决这个问题。

Answer 1

您可以尝试这样的事情：

SELECT Contactid FROM <YOURTABLE> 
WHERE ruleid = 2 
AND Contactid NOT IN 
    (SELECT Contactid FROM <YOURTABLE> 
     WHERE ruleid <> 2)

Answer 2

WITH your_table_name as(
        SELECT 1 AS Contactid   , 2 AS ruleid FROM DUAL
        UNION ALL
        SELECT 5 AS Contactid   , 3 AS ruleid FROM DUAL
        UNION ALL
        SELECT 5 AS Contactid   , 2 AS ruleid FROM DUAL
        UNION ALL
        SELECT 6 AS Contactid   , 4 AS ruleid FROM DUAL
        UNION ALL
        SELECT 6 AS Contactid   , 2 AS ruleid FROM DUAL
        UNION ALL
        SELECT 7 AS Contactid   , 2 AS ruleid FROM DUAL
)

SELECT t.* FROM (
      SELECT   Contactid   FROM  your_table_name
      WHERE ruleid = 2
      GROUP BY   Contactid 
      HAVING COUNT(*) = 1
    ) t
    left JOIN (
      SELECT   Contactid   FROM  your_table_name
      WHERE ruleid <> 2
      GROUP BY   Contactid 
    ) tt
    ON
    t.Contactid = tt.Contactid
    where tt.Contactid is null

Answer 3

这样的事情应该有效并且效率很高。

select   contactid
from     table_name
group by contactid
having   min(ruleid) = 2 
     and max(ruleid) = 2

Answer 4

这对你来说还不够吗？

select contactid from table group by contactid having count(ruleid)=1

Oracle sql从重复项中查找单行

4 个答案: