I have created one table in PL SQL Developer.

```
CREATE TABLE Patient_List
(
   Patient_ID number NOT NULL,
   Patient_Name varchar(50) NOT NULL,
   Patient_Address varchar(100) NULL,
   App_Date date NULL,
   Descr varchar(50),
   CONSTRAINT patient_pk PRIMARY KEY(Patient_ID)
);

```

I want to auto increment Patient\_ID, I tried altering the table and modifying the Patient\_ID column but it's showing an error "invalid ALTER TABLE option"

```
ALTER TABLE Patient_List
MODIFY Patient_ID NUMBER NOT NULL GENERATED ALWAYS AS IDENTITY;

```

Please help, Thanks in advance.