SUBSTR返回的是一个字符串,
SELECT SUBSTR(A,1) FROM TABLE1
UNION SELECT B FROM TABLE2B是VARCHAR时, 就会提示不匹配,
怎么改一下可以呢, 最好是改变SUBSTR(A,1)
SELECT SUBSTR(A,1) FROM TABLE1
UNION SELECT B FROM TABLE2B是VARCHAR时, 就会提示不匹配,
怎么改一下可以呢, 最好是改变SUBSTR(A,1)
SQL>
SQL> select 'aaa' from dual
2 union
3 select 'bb ' from dual
4 ;'AAA'
------
aaa
bb
UNION SELECT B FROM TABLE2
SUBSTR(A,1)返回的是字符串类型的 , B 是VARCHAR类型的, 怎么通过转换使这个类型一样,
B 是NUMBER型的呢, 怎么转换呢
SELECT Substr('aaa',1,1) FROM dual
UNION SELECT 'b' FROM dual
S
-
a
bB 是NUMBER型,直接截取就可以了[code=SQL]
SELECT substr(111111,1,1) FROM dual
UNION SELECT 'b' FROM dualS
-
1
b[code=SQL]
不知道是不是楼主要的结果.
UNION
SELECT to_char(b) FROM dual
UNION SELECT substr(B,1,3) FROM TABLE2
這樣應該就可以啊
SELECT substr('A',1,1) FROM dual
UNION
SELECT 'AAA' FROM dual;