查询出俩个表的不同的字段//witht求差集也可以TableTable2IDID112233465//table比table2多4,5；table2比tabel多6.WITHTAS(SELECT1COL1FROMDUALUNIONALLSELECT2COL1FROMDUALUNIONALLSELECT3COL1FROMDUALUNI

Question

查询出俩个表的不同的字段//with t
求差集也可以
Table Table2
ID ID
1 1
2 2
3 3
4 6
5
//table 比table2 多 4,5 ；table2 比 tabel 多 6 .
WITH T AS
(SELECT 1 COL1 FROM DUAL UNION ALL
SELECT 2 COL1 FROM DUAL UNION ALL
SELECT 3 COL1 FROM DUAL UNION ALL
SELECT 4 COL1 FROM DUAL UNION ALL
SELECT 5 COL1 FROM DUAL
),
t2 as
(SELECT 1 COL2 FROM DUAL UNION ALL
SELECT 2 COL2 FROM DUAL UNION ALL
SELECT 3 COL2 FROM DUAL UNION ALL
SELECT 6 COL2 FROM DUAL
)
select '1表比2表多' memo ,t.col1 id from t
minus
select '1表比2表多' memo ,t2.col2 id from t2
UNION
select '2表比1表多' memo ,t2.col2 id from t2
minus
select '2表比1表多' memo ,t.col1 id from t
;

Answer 1

公用表表达式,这个你详细用法你可以查数据库的联机丛书,因为比较多
不过简单将就是把as后面的部分当做一个临时视图来使用