要知道' 也是转义字符: SQL> select '' as test from dual;TEST ----SQL> select '''' as test from dual;TEST ---- 'SQL> select 'kevin''s book' as test from dual;TEST ------------ kevin's bookSQL>
引号是字符, 可以用字符串打印出来 如SQL> select "kevin''s book" as test from dual;
有转义字符的用法,在pl/sql中试一下就知道了!
其实可以用另一种标记方式的,q'!...!',首字母是q或Q,外面用一对引号,引号内一对字符,该字符可以是任意的,只要不在你的字符串中出现就行,中间就是你要表示的字符串,不用管里面有多少引号,如你要显示:I'm a string, you're a string.只要写成:q'!I'm a string, you're a string.!'就行了
SQL> select '' as test from dual;TEST
----SQL> select '''' as test from dual;TEST
----
'SQL> select 'kevin''s book' as test from dual;TEST
------------
kevin's bookSQL>
可以用字符串打印出来
如SQL> select "kevin''s book" as test from dual;
看过大家的讨论,
对引号有了深一步的了解!!
散分了