Один из способов вставки нескольких строк в таблицу приведен ниже:
INSERT ALL
INTO mytable (column1, column2, column_n) VALUES (expr1, expr2, expr_n)
INTO mytable (column1, column2, column_n) VALUES (expr1, expr2, expr_n)
INTO mytable (column1, column2, column_n) VALUES (expr1, expr2, expr_n)
SELECT * FROM dual;
В вашем случае
INSERT ALL
INTO CUSTOMER (Customer_ID,Customer_Name,Customer_Age,Customer_City ) VALUES (1,'Simon Li',21,'New York')
INTO CUSTOMER (Customer_ID,Customer_Name,Customer_Age,Customer_City ) VALUES (2,'Richard Andrew',34,'San Diego')
INTO CUSTOMER (Customer_ID,Customer_Name,Customer_Age,Customer_City ) VALUES (3,'Catherine Wong',34,'Tuscon')
INTO CUSTOMER (Customer_ID,Customer_Name,Customer_Age,Customer_City ) VALUES (4,'Marie',28,'Tuscon')
INTO CUSTOMER (Customer_ID,Customer_Name,Customer_Age,Customer_City ) VALUES (5,'Bob Richard',27,'San Diego')
SELECT * FROM dual;
, а также вам не хватает типа данных для столбца Customer_Age, Возраст не более 3 цифр, поэтому мы можем объявить его как НОМЕР (3)
CREATE TABLE CUSTOMER
(
Customer_ID INT PRIMARY KEY,
Customer_Name VARCHAR2(25),
Customer_Age NUMBER(3),
Customer_City VARCHAR2(20)
);