Question

How can we set default value for a number typed column has ’00’?I tried this but it still saved it has ‘0’,I need to do this.

//alter table table_name add column column1 default '00';

Please suggest a way for me.

Answer 1

It is not possible to store numbers like that – In a format you have described (’00’). You can store numbers as numbers (as values of numeric data type of course) and use to_char function or to_char function combined with lpad function to represent numbers in a format you like. Here is an example:

SQL> create table TB_SingleNumberColumn(
  2    col number
  3  )
  4  /

Table created
SQL> insert into TB_SingleNumberColumn(Col) values(1);

1 row inserted

SQL> insert into TB_SingleNumberColumn(Col) values(5);

1 row inserted

SQL> insert into TB_SingleNumberColumn(Col) values(11);

1 row inserted

SQL> insert into TB_SingleNumberColumn(Col) values(111);

1 row inserted

SQL> commit;

Commit complete

-- The values as they are
SQL> select * from TB_SingleNumberColumn;

       COL
----------
         1
         5
        11
       111

-- Values padded with zeros.
SQL> select to_char(col, '000') res 
  2   from TB_SingleNumberColumn;

RES
----
 001
 005
 011
 111 

SQL> select lpad(to_char(col), 3, '0')
  2    from TB_SingleNumberColumn
  3  ;

LPAD(TO_CHAR(COL),3,'0')
------------------------
001
005
011
111