title: Error Code 1452 When attempting to Alter Table Constraint
body: <pre><code>ALTER TABLE `charter`
    ADD CONSTRAINT `charter_ibfk_3` FOREIGN KEY (`CHAR_DESTINATION`) 
    REFERENCES `airport` (`AIRPORT_CODE`);
  </code></pre>
  
  <p>I am attempting to create this relationship:</p>
  
  <p><a href="https://i.stack.imgur.com/RTNkv.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RTNkv.jpg" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/RTNkv.jpg" rel="nofollow noreferrer">Charter and Airport ERD Diagram</a></p>
  
  <pre><code>CREATE TABLE `antonellacammarota` (
    `CUS_CODE` int(6) NOT NULL DEFAULT '0',
    PRIMARY KEY (`CUS_CODE`),
    FOREIGN KEY (`CUS_CODE`) REFERENCES `CUSTOMER` (`CUS_CODE`)
  ) ENGINE=InnoDB DEFAULT CHARSET=latin1;
  
  insert into customer values (10076, "Cammarota", "Antonella", "T", "805", "555-1212", 0);
  
  insert into antonellacammarota(select cus_code from customer where cus_lname = 'Cammarota');
  
  --
  -- Table structure for table `airport`
  --
  
  CREATE TABLE IF NOT EXISTS `airport` (
    `AIRPORT_CODE` varchar(3) NOT NULL DEFAULT '0',
    `AIRPORT_NAME` varchar(40) DEFAULT NULL,
    `AIRPORT_ADDRESS` varchar(45) DEFAULT NULL,
    `AIRPORT_CITY` varchar(25) DEFAULT NULL,
    `AIRPORT_STATE` char(2) DEFAULT NULL,
    `AIRPORT_ZIP` varchar(10) DEFAULT NULL,
    `AIRPORT_COUNTRY` varchar(25) DEFAULT NULL,
    `AIRPORT_AREACODE` varchar(3) DEFAULT NULL,
    `AIRPORT_PHONE` varchar(8) DEFAULT NULL,
    PRIMARY KEY (`AIRPORT_CODE`)
  ) ENGINE=InnoDB DEFAULT CHARSET=latin1;
  
  --
  -- Constraints for table `airport`
  --
  ALTER TABLE `charter`
    ADD CONSTRAINT `charter_ibfk_3` FOREIGN KEY (`CHAR_DESTINATION`) REFERENCES `airport` (`AIRPORT_CODE`);
  
  
  --
  -- Dumping data for table `airport`
  --
  
  INSERT INTO `airport` (`AIRPORT_CODE`, `AIRPORT_NAME`, `AIRPORT_ADDRESS`, `AIRPORT_CITY`, `AIRPORT_STATE`, 
  `AIRPORT_ZIP`, `AIRPORT_COUNTRY`, `AIRPORT_AREACODE`, `AIRPORT_PHONE`) VALUES
  ('ATL', 'Hartsfield-Jackson Atlanta Int', '6000 N Terminal Pkwy.', 'Atlanta', 'GA', '30320', 'US', '808', '897-1910'),
  ('BNA', 'Nashville Int', '1 Terminal Dr.', 'Nashville', 'TN', '37214', 'US', '615', '275-1675'),
  ('GNV', 'Gainesville Regional', '3880 NE 39th Ave.', 'Gainesville', 'FL', '32609', 'US', '352', '373-0249'),
  ('MOB', 'Mobile Regional', '8400 Airport Blvd.', 'Mobile', 'AL', '36608', 'US', '800', '357-5373'),
  ('MOY', 'Monterrey', '', 'Monterrey', '', '', 'Columbia', '', ''),
  ('STL', 'St. Louis Lambert Int', '10701 Lambert International Blvd.', 'St. Louis', 'MO', '63145', 'US', '314', '426-8000'),
  ('TYS', 'McGhee Tyson', '2055 Alcoa Hwy', 'Alcoa', 'TN', '37701', 'US', '865', '345-3000');
  </code></pre>