MySql: The customer has multiple addresses only one is primary - mysql

Question

I don't think I planned and organized the table well, so please consider and advise me how to solve this.
In my application I have to ensure that customers can have multiple addresses only one of those addresses must be marked as primary. The primary address is used as the delivery address, etc.
I have customer table and i create new relation table customer_addresses.
CREATE TABLE `customer_addresses` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`custemer_id` int(11) DEFAULT NULL,
`primary_adddrss` tinyint(1) DEFAULT NULL,
`address` varchar(225) DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `custemer_id_UNIQUE` (`custemer_id`),
UNIQUE KEY `primary_UNIQUE` (`primary_adddrss`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
This table must contain all the addresses of all customers but only one address from a specific customer must be primary and customer can have only one primary address. That is reson whay i put two unique index.
If i remove custemer_id unique only one primary address can be in whole table for all customers.
Only one primary address per customer other non-primary addresses are null.
Table
id | customer_id | primary_address | address
--------------------------------------------------------
1 1 1 Test
This above customer have only one primary address. Now i want to insert for the some customer more non-primary addresses.
When i try to insert
INSERT INTO `table`.`customer_addresses`(`id`,`custemer_id`,`primary_adddrss`,`address`)
VALUES (1, null ,'Test 2');
I get error
1062: Duplicate entry '1' for key 'primary_UNIQUE'
If i remove primary_UNIQUE than all cusomers can have only one primary. I need one customer only one primary.
How to redesign table to slove this?
Thanks

Answer 1

If the customer may have a lot of different addresses then you have 1:N relation. Create separate addresses table which refers to customers table. Add a column which marks primary address and restrict with only one mark per customer_id.
Schematically (no syntax):
CREATE TABLE customer ( customer_id PRIMARY KEY, ... );
CREATE TABLE address ( address_id PRIMARY KEY,
-- reference to customer
customer_id NOT NULL REFERENCES customer (customer_id),
-- can be either 1 or NULL
is_primary BOOLEAN NULL CHECK (is_primary = 1),
-- allows one 1 and many NULL per customer
UNIQUE (customer_id, is_primary),
... );
DEMO

Answer 2

Option 1 :
CREATE TABLE `customer_addresses` ( `id` INT NOT NULL AUTO_INCREMENT ,
`customer_id` INT NOT NULL ,
`primary_address` TEXT NOT NULL ,
`addresses` TEXT NOT NULL ,
PRIMARY KEY (`id`)) ENGINE = InnoDB;
you can save primary address in primary_address column, and other addresses is saved in addresses column as array
Option 2 :
CREATE TABLE `customer_addresses` ( `id` INT NOT NULL AUTO_INCREMENT ,
`customer_id` INT NOT NULL ,
`is_primary` BOOLEAN NOT NULL ,
`addresses` TEXT NOT NULL ,
PRIMARY KEY (`id`)) ENGINE = InnoDB;
just save all address as usual, and marks the primary address with is_primary=1 and the non-primary address with is_primary=0