在SQL中更改表脚本

Question

If i have a table_abc. Now i alter and add few columns in this like

alter table_Abc add ( congif_id number, sso number);

Now second time i add few columns along with congif_id and sso like :

alter table_Abc add ( congif_id number, sso number,name varchar2(100));

but this is throwing error column already exists.

Shouldnt the alter script still run even if the names are same and add the new ones ?

Answer 1

No, that error is to be expected. If necessary you can make your DDL script re-runnable using dynamic SQL, for example:

begin
   execute immediate
   'alter table table_Abc add ( congif_id number)';
exception
   when others then 
      if sqlcode = -1430 then
         null;
      end if;
end;

begin
   execute immediate
   'alter table table_Abc add ( sso number)';
exception
   when others then 
      if sqlcode = -1430 then
         null;
      end if;
end;
...

Or if you do this sort of thing a lot:

declare
   procedure run_ddl
      ( p_sql varchar2
      , p_ignored_exception integer
      )
   is
   begin
      execute immediate p_sql;
   exception
      when others then 
         if sqlcode = p_ignored_exception then
            null;
         end if;
   end;
begin
   run_ddl ('alter table table_Abc add ( congif_id number)', -1430);
   run_ddl ('alter table table_Abc add ( sso number)', -1430);
end;