Not able to create a Foreign Constraint in Mysql - mysql

Question

Here is the script I am trying to run
CREATE TABLE IF NOT EXISTS `store` (
`store_id` INT NOT NULL AUTO_INCREMENT,
`store_name` VARCHAR(1024) NOT NULL,
`store_user` INT NOT NULL,
`store_address` INT NOT NULL,
`store_type` INT NOT NULL,
`created_date` DATETIME NOT NULL,
`updated_date` DATETIME NOT NULL,
PRIMARY KEY (`store_id`)
ENGINE = InnoDB;
CREATE TABLE IF NOT EXISTS `store_address` (
`address_id` INT NOT NULL AUTO_INCREMENT,
`address_line_1` VARCHAR(1024) NOT NULL,
`address_line_2` VARCHAR(1024) NOT NULL,
`address_line_3` VARCHAR(1024) NULL,
`city` VARCHAR(45) NOT NULL,
`locality` VARCHAR(100) NOT NULL,
`pincode` CHAR(6) NOT NULL,
`latitude` DECIMAL(8,6) NULL,
`longitude` DECIMAL(9,6) NULL,
`state` VARCHAR(45) NOT NULL,
`created_date` DATETIME NOT NULL,
`updated_date` DATETIME NOT NULL,
PRIMARY KEY (`address_id`),
CONSTRAINT `FK_STR_STR_ADR`
FOREIGN KEY (`address_id`)
REFERENCES `store` (`store_address`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
I get this error - Error Code: 1215. Cannot add foreign key constraint
No clue what is wrong with the DDL

Answer 1

Two issues:
1. use unsigned int for the primary keys (Edit: this is a good idea but was not the problem)
2. the store.store address must be a key in the store table in order to use it in a foreign key constraint in the store_address table
CREATE TABLE IF NOT EXISTS `store` (
`store_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`store_name` VARCHAR(1024) NOT NULL,
`store_user` INT NOT NULL,
`store_address` int(10) unsigned NOT NULL DEFAULT 0,
`store_type` INT NOT NULL,
`created_date` DATETIME NOT NULL,
`updated_date` DATETIME NOT NULL,
PRIMARY KEY (`store_id`),
KEY (`store_address`)
) ENGINE = InnoDB;
CREATE TABLE IF NOT EXISTS `store_address` (
`address_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`address_line_1` VARCHAR(1024) NOT NULL,
`address_line_2` VARCHAR(1024) NOT NULL,
`address_line_3` VARCHAR(1024) NULL,
`city` VARCHAR(45) NOT NULL,
`locality` VARCHAR(100) NOT NULL,
`pincode` CHAR(6) NOT NULL,
`latitude` DECIMAL(8,6) NULL,
`longitude` DECIMAL(9,6) NULL,
`state` VARCHAR(45) NOT NULL,
`created_date` DATETIME NOT NULL,
`updated_date` DATETIME NOT NULL,
PRIMARY KEY (`address_id`),
CONSTRAINT `FK_STR_STR_ADR` FOREIGN KEY (`address_id`) REFERENCES `store` (`store_address`)
)ENGINE = InnoDB;