Automatic varchar2 and number conversion of pure numbers in Oracle

Automatic varchar2 and number conversion of pure numbers in Oracle

When an association query is used, the fields in the two tables define different types. One field is of the varchar2 type, and the other is of the number type. The content is as follows: '20160301' and 00187. In use, the varchar2 type is automatically converted to number, that is, 187 and 187.

The effect is the same as that of to_number.

I wrote two SQL statements for test, as shown below:

Select
Case when '000000' = 0110 then
'True'
Else
'False'
End
From dual;
Select
Case when to_number ('123') = to_number (0110) then
'True'
Else
'False'
End
From dual;

The result is true.

However, to_number () is better for the sake of insurance.