ORA-01722: invalid number
今天开发遇到一个问题，两个不同的用户，下面都有一张表，表的结构一样，数据不一样，列是varchar2类型的，a用户执行查询select xx from xx where xx=1;可以出结果，b用户查询自己的表就报错ORA-01722: invalid number。开发怀疑是用户的权限不一样导致的。
因为，oracle使用了隐式的转换，to_number(xxx)=1，如果xxx列里面有不能转换为数字的，则报错。
下面进行验证
SQL> create table gw1(name varchar2(5));
Table created.
SQL> insert into gw1 values(1);
1 row created.
SQL> commit;
Commit complete.
SQL> select * from gw1 where name=1;
NAME
----------
1
SQL> truncate table gw1;
Table truncated.
SQL> insert into gw1 values('a');
1 row created.
SQL> commit;
Commit complete.
SQL> select * from gw1 where name=1;
select * from gw1 where name=1
*
ERROR at line 1:
ORA-01722: invalid number
SQL> insert into gw1 values(1);
1 row created.
SQL> insert into gw1 values(2);
1 row created.
SQL> commit;
Commit complete.
SQL> select * from gw1 where name=1;
select * from gw1 where name=1
*
ERROR at line 1:
ORA-01722: invalid number
SQL> explain plan for select * from gw1 where name=1;
Explained.
SQL> select * from table(dbms_xplan.display);
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Plan hash value: 3401378285
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 4 | 3 (0)| 00:00:01 |
|* 1 | TABLE ACCESS FULL| GW1 | 1 | 4 | 3 (0)| 00:00:01 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter(TO_NUMBER("NAME")=1)----------------------------
然后检查两个用户的两个表，发现不报错的用户的表里面的字段都是数字，而报错的用户表里面的字段有字母。