Return 来自 Table 2 个来自 Table1 上相同名称的不同 ID

Question

我一直在尝试开发一个查询来解决问题，但它很难。

Table 1:

+------+----+
| NAME | ID |
+------+----+
| A    |  1 |
| A    |  2 |
| B    |  1 |
| B    |  5 |
| C    |  8 |
+------+----+

Table 2:

+------+----+
| NAME | ID |
+------+----+
| A    |  1 |
| A    |  4 |
| B    |  3 |
| B    |  5 |
| D    |  9 |
+------+----+

根据这些结果，我需要 return table 2 中名称包含在 table 1 而 ID 不包含的所有内容。

所以，在这个例子中，return 应该是：

+------+----+
| NAME | ID |
+------+----+
| A    |  4 |
| B    |  3 |
+------+----+

Answer 1

您可以使用 NOT EXISTS 或类似的：

SELECT  t2.*
FROM Table2 t2
WHERE NOT EXISTS
(
   SELECT 1
   FROM Tabl1 t1
   WHERE t1.Name = t2.Name
   AND t1.Id = t2.Id
);

Answer 2

SELECT T1.ID,T1.NAME
FROM TABLE2 T1 INNER JOIN TABLE1 T2 ON T1.NAME = T2.NAME
               LEFT JOIN TABLE1 T3 ON T3.ID = T1.ID
WHERE T3.ID IS NULL

Answer 3

你可能想试试这个：

编辑：用 WITH 子句中的简单子查询替换了 table1 和 table2。

WITH table1 AS
(
SELECT
  DECODE(LEVEL,1, 'A',2, 'A',3, 'B',4, 'B',5, 'C') AS name
  ,DECODE(LEVEL,1, 1,2, 2,3, 1,4, 5,5, 8) AS id
FROM
  dual
CONNECT BY LEVEL < 6
)
,table2 AS
(
SELECT
  DECODE(LEVEL,1, 'A',2, 'A',3, 'B',4, 'B',5, 'D') AS name
  ,DECODE(LEVEL,1, 1,2, 4,3, 3,4, 5,5, 9) AS id
FROM
  dual
CONNECT BY LEVEL < 6
)
SELECT
  t2.id
  ,t2.name
FROM
  table1 t1
  ,table2 t2
WHERE
  t1.name = t2.name -- here we take all the records from table2, which have the same names as in table1
MINUS -- then we "subtract" the records that have both the same name and id in both tables
SELECT
  t2.id
  ,t2.name
FROM
  table1 t1
  ,table2 t2
WHERE
  t1.name = t2.name
  AND t1.id = t2.id

Answer 4

我会做：

with t1 as (select 'A' name, 1 id from dual union all
            select 'A' name, 2 id from dual union all
            select 'B' name, 1 id from dual union all
            select 'B' name, 5 id from dual union all
            select 'C' name, 8 id from dual),
     t2 as (select 'A' name, 1 id from dual union all
            select 'A' name, 4 id from dual union all
            select 'B' name, 3 id from dual union all
            select 'B' name, 5 id from dual union all
            select 'D' name, 9 id from dual)
select name, id
from   t2
where  name in (select name from t1)
minus
select name, id
from   t1;

NAME         ID
---- ----------
A             4
B             3

Return 来自 Table 2 个来自 Table1 上相同名称的不同 ID

Return from Table 2 different Ids from same names on Table1

sql

oracle

inner-join

outer-join