Compare varchar with number

Question

Hi,
I had a problem as below:
Create table Test (col1 varchar2(20));
insert into Test (col1) values ('123');
insert into Test (col1) values ('ABC');
select * from Test Where col1 = 123;
I get following error:
ORA-01722: invalid number
select * from Test Where col1 = '123';
select successful.
But when I perform following step:
Delete from Test;
insert into Test (col1) values ('123');
insert into Test (col1) values ('234');
insert into Test (col1) values ('345');
select * from Test WHERE col1 = 123;
Select successful.
I just query why I can't compare 1 number to a varchar2 column when there is character record in that column. I'm using Oracle DB 10.2.0.2 and I believe oracle should be allow implicit convert between number char varchar2. Do I miss anything to make my first select statement return with the record I need?
Thank in advance.
Eng Khoon

Answer 1

Hi,
I had some new input for this post i created yesterday.
Let say i create a new table with 2 column
Create table test (col1 varchar2(30), col2 varchar2(30))
I insert following data into the table
col1 col2
123 ABC
ABC BCD
234 ABC
345 ABC
BCD BCD
I perform following select statement from above data:
select * from test where col2='ABC' and col1=123
I perform this test in my local DB (10.2.0.2) and I can successful selected out 3 rows;
But when i perform same select statement in my server DB (10.2.0.2), it complain ORA-01722: invalid number
Please help! Anything I can set so that my server also allow to perform the similar select statement?
Thanks.