MySQL - Nonsense Syntax Errors - mysql

Question

I'm new to programming, and cannot understand the syntax errors that I'm getting.
CREATE SCHEMA IF NOT EXISTS donutsrus;
CREATE TABLE IF NOT EXISTS DONUT (
Donut_ID INT NOT NULL, UNIQUE
Donut_Name VARCHAR (20) NOT NULL, UNIQUE
Description VARCHAR (20) NOT NULL, UNIQUE
Unit_Price NUMERIC (4,2) NOT NULL
PRIMARY KEY (Donut_ID));
CREATE TABLE IF NOT EXISTS SALES_ORDER (
Sales_Order_ID INT NOT NULL, UNIQUE
Sales_Order_Date DATE NOT NULL
Sales_Order_Notes VARCHAR (100)
Customer_ID INT NOT NULL, UNIQUE
PRIMARY KEY (Sales_Order_ID)
FOREIGN KEY (Customer_ID));
CREATE TABLE IF NOT EXISTS CUSTOMER (
Customer_ID INT NOT NULL, UNIQUE
Last_Name VARCHAR (20) NOT NULL
First_Name VARCHAR (20) NOT NULL
Address VARCHAR (50) NOT NULL
Apt VARCHAR (5)
City VARCHAR (20) NOT NULL
State CHAR (2) NOT NULL
Zip NUMBER (5) NOT NULL
Home_Phone NUMBER (10)
Mobile_Phone NUMBER (10)
Other_Phone NUMBER (10)
PRIMARY KEY (Customer_ID));
CREATE TABLE IF NOT EXISTS ORDER_LINE_ITEM (
Donut_ID INT NOT NULL, UNIQUE
Sales_Order_ID INT NOT NULL, UNIQUE
Quantity INT NOT NULL
PRIMARY KEY (Donut_ID, Sales_Order_ID)
FOREIGN KEY (Donut_ID, Sales_Order_ID));
On the Donut table, I get Syntax error: extraneous input found - expected 'opening parenthesis', at the VARCHAR after Donut_Name. At the closing paren after the succeeding 20, I get Syntax error: extraneous input found - expected 'closing parenthesis'.
On the Order Line Item table I get, Syntax Error: 'INT' (int) is not valid input at this position, after the Sales_Order_ID. I also don't understand why it's okay on other lines of code, but not this one.

Answer 1

All the commas before UNIQUE are wrong. Commas are used to separate the columns, not to separate options for a specific column.
CREATE TABLE IF NOT EXISTS DONUT (
Donut_ID INT NOT NULL UNIQUE,
Donut_Name VARCHAR (20) NOT NULL UNIQUE,
Description VARCHAR (20) NOT NULL UNIQUE,
Unit_Price NUMERIC (4,2) NOT NULL,
PRIMARY KEY (Donut_ID));
CREATE TABLE IF NOT EXISTS CUSTOMER (
Customer_ID INT NOT NULL UNIQUE,
Last_Name VARCHAR (20) NOT NULL,
First_Name VARCHAR (20) NOT NULL,
Address VARCHAR (50) NOT NULL,
Apt VARCHAR (5),
City VARCHAR (20) NOT NULL,
State CHAR (2) NOT NULL,
Zip NUMBER (5) NOT NULL,
Home_Phone NUMBER (10),
Mobile_Phone NUMBER (10),
Other_Phone NUMBER (10),
PRIMARY KEY (Customer_ID));
CREATE TABLE IF NOT EXISTS SALES_ORDER (
Sales_Order_ID INT NOT NULL UNIQUE,
Sales_Order_Date DATE NOT NULL,
Sales_Order_Notes VARCHAR (100),
Customer_ID INT NOT NULL,
PRIMARY KEY (Sales_Order_ID),
FOREIGN KEY (Customer_ID) REFERENCES CUSTOMER (Customer_ID));
CREATE TABLE IF NOT EXISTS ORDER_LINE_ITEM (
Donut_ID INT NOT NULL,
Sales_Order_ID INT NOT NULL,
Quantity INT NOT NULL,
PRIMARY KEY (Donut_ID, Sales_Order_ID),
FOREIGN KEY (Donut_ID) REFERENCES DONUT (Donut_ID),
FOREIGN KEY (Sales_Order_ID) REFERENCES SALES_ORDER (Sales_Order_ID));
BTW, the UNIQUE option is not necessary for primary keys, they're automatically made unique. And in ORDER_LINE_ITEM, if the primary key is (Donut_ID, Sales_Order_ID) you probably don't want to make each of those columns unique by themselves. This prevents the same donut from being in multiple orders, or an order having more than one donut type. Similarly, Customer_ID should not be unique in SALES_ORDER; a customer can obviously have more than one order.
Your FOREIGN KEY lines were missing the references of the foreign keys. And the tables with the foreign keys need to be created after the tables they reference, so I moved SALES_ORDER down to after CUSTOMER.