первичный ключ
CREATE TABLE Persons (
Rollno int NOT NULL,
FirstName varchar(255),
LastName varchar(255),
Age int,
PRIMARY KEY (ID)
);
sree_007
CREATE TABLE Persons (
Rollno int NOT NULL,
FirstName varchar(255),
LastName varchar(255),
Age int,
PRIMARY KEY (ID)
);
CREATE TABLE purchase_orders (
po_nr NUMBER,
vendor_id NUMBER NOT NULL,
po_status NUMBER(1,0) NOT NULL,
created_at TIMESTAMP WITH TIME ZONE NOT NULL,
CONSTRAINT pk_purchase_orders PRIMARY KEY(po_nr)
);