浅谈oracle中单引号转义

SQL> select '''' result from dual; 
RESULT 
------ 
'   

select ' '' ' from dual; 
output:' 
//  

SQL> select 'name'||'''' result from dual; 
RESULT 
------ 
name'  

SQL> select 'name''''' result from dual; 
RESULT 
------ 
name'' 

SQL> select 'hh24"小时""mi""分"""ss"秒"' results from dual; 
RESULTS 
------------------------- 
hh24"小时""mi""分"""ss"秒" 
//  

SQL> select to_char(sysdate,'hh24"小时"mi"分"ss"秒"') results from dual; 
RESULTS 
-------------- 
06小时39分51秒 
//  

select to_char(sysdate, 'hh24') || '小时' || 
    to_char(sysdate, 'mi') || '分' || 
    to_char(sysdate, 'ss') || '秒' 
    AS RESULT  
from dual; 
RESULT 
-------------- 
06小时40分18秒

create table t_test1(str_sql varchar2(2000));
create table t_test2(str_sql varchar2(2000),cnt number(10));
truncate table t_test1;
truncate table t_test2;
insert into t_test1 select table_name from user_tables;
commit;
--------
set serveropput on;
declare
vv_name varchar2(200):='';
vv_cnt number(10):=0;
vv_sql varchar2(2000):='';
begin
 for usr in (select str_sql from t_test1)
  loop
  vv_sql := rtrim('insert into t_test2 SELECT '''||usr.str_sql|| ''',COUNT(1) FROM ' || usr.str_sql,';');
  dbms_output.put_line(vv_sql);
  execute immediate vv_sql;  
  commit; 
end loop;
  commit;
end;
  vv_sql := rtrim('insert into t_test2 SELECT '''||usr.str_sql|| ''',COUNT(1) FROM ' || usr.str_sql,';');
rtrim(a,b):

 'insert into t_test2 SELECT '''||usr.str_sql|| ''',COUNT(1) FROM ' || usr.str_sql
 'insert into t_test2 SELECT '''
1                  234
==> 单引号之中是 insert into t_test2 SELECT '

|| --连接字符串
usr.str_sql
|| --连接字符串
 ''',COUNT(1) FROM '
123            4

==> ',COUNT(1) FROM 
 ||  --连接字符串
usr.str_sql 

==> insert into t_test2 SELECT 'usr.str_sql',COUNT(1) FROM usr.str_sql