How to select rows where for a column there are two rows one with null and another with non-null value then select only row with non-null value

If you have a condition that specifies 1005 whether root_id has to get the same value as unique_id, you could use a TRIGGER. Something like this:

CREATE OR REPLACE TRIGGER root_unique_trg
    BEFORE INSERT
    ON UNIQUE_PHYSICIAN
    FOR EACH ROW
    WHEN (NEW.is_root_phys = 1)
BEGIN
    :NEW.root_id := :NEW.unique_id ;
END ;

Tested in SQLfiddle

You could just use %_99_% instead of %99%.

• % means 0 ore more characters
• _ means exactly 1 character

So %_99_% means at least 1 character before and after 99, and anything before and after.

SQL> select * from t1;

C1
--------------------
1991
1199
9911

SQL> select * from t1 where c1 like '%_99_%';

C1
--------------------
1991