Add a constraint to a column on an Oracle table so that only positive values are allowed I'm not allowed to drop the table, or delete the columns.
The task is to add a constraint to a column possibly by using an ALTER statement so that it disallows any negative numbers. Is this possible?

I tried the following:

SQL&gt; alter table SPEND_PLAN_DETAIL_VALUE modify (SP_DETAIL_VALUE_ID CHECK (SP_DETAIL_VALUE_ID &gt; 0));


but this doesn't work.
To add a constraint you need to use add constraint:

alter table SPEND_PLAN_DETAIL_VALUE 
  add constraint check_detailvalue CHECK (SP_DETAIL_VALUE_ID &gt; 0);


Online example