ORA-01858 FOR BEGINNER - sql

Question

CREATE TABLE Pizza
(
pizza_id DECIMAL(12) NOT NULL PRIMARY KEY,
name VARCHAR(32) NOT NULL,
date_available DATE NOT NULL,
price DECIMAL(4,2) NOT NULL
);
CREATE TABLE Topping
(
topping_id DECIMAL(12) NOT NULL,
topping_name VARCHAR(64) NOT NULL,
pizza_id DECIMAL(12)
);
ALTER TABLE Topping
ADD CONSTRAINT topping_pk PRIMARY KEY(topping_id);
ALTER TABLE Topping
ADD CONSTRAINT Topping_pizza_fk
FOREIGN KEY(pizza_id) REFERENCES Pizza(pizza_id);
INSERT INTO pizza (pizza_id, name, date_available, price)
VALUES (1, 'Plain', CAST('27-Feb-2021' AS DATE), 6);
Error:
ORA-01858: a non-numeric character was found where a numeric was expected
I cannot figure out which part is wrong, I'm just a beginner for SQL, it seems related with date, can someone help me?

Answer 1

This works for me: SQL Fiddle. Don't use CAST to convert strings to dates. That's the only thing that looks off about your example. It may be using a different default date format than your string. Instead use TO_DATE( '27-Feb-2021', 'DD-Mon-YYYY') which converts a string to a date, or DATE '2021-02-27', which is a date literal and only takes the yyyy-mm-dd format.
Additionally, I'd suggest using NUMBER instead of DECIMAL just because it's more standard in the Oracle world. And always use VARCHAR2 instead of VARCHAR, which is officially discouraged.