MySQL Error 1452 when inserting data

Question

I keep getting errors when importing my old SQL file and fix them all,but I'm stuck and can't understand what this means.

ALTER TABLE property ADD CONSTRAINT property_ibfk_1 FOREIGN KEY (intid) REFERENCES interiors (id) ON DELETE CASCADE ON UPDATE CASCADE, ADD CONSTRAINT property_ibfk_2 FOREIGN KEY (owner) REFERENCES accounts (id) ON DELETE SET NULL ON UPDATE CASCADE MySQL said: Documentation

1452 - Cannot add or update a child row: a foreign key constraint fails (ionicnew.#sql-252c_e1, CONSTRAINT property_ibfk_2 FOREIGN KEY (owner) REFERENCES accounts (id) ON DELETE SET NULL ON UPDATE CASCADE)

Full code of property table:

CREATE TABLE `property` (
  `id` int(11) NOT NULL,
  `x` float NOT NULL,
  `y` float NOT NULL,
  `z` float NOT NULL,
  `a` float NOT NULL,
  `type` bit(32) NOT NULL,
  `intid` int(11) NOT NULL,
  `name` varchar(128) NOT NULL,
  `price` int(11) NOT NULL,
  `mapicon` tinyint(3) UNSIGNED NOT NULL,
  `status` tinyint(3) UNSIGNED NOT NULL,
  `point` int(10) UNSIGNED NOT NULL,
  `saleprice` int(11) NOT NULL DEFAULT '0',
  `owner` int(11) DEFAULT NULL,
  `money` int(11) NOT NULL DEFAULT '0',
  `level` tinyint(3) UNSIGNED NOT NULL DEFAULT '0'
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

ALTER TABLE `property`
  ADD PRIMARY KEY (`id`),
  ADD KEY `intid` (`intid`),
  ADD KEY `owner` (`owner`);

ALTER TABLE `property`
  MODIFY `id` int(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=86;

ALTER TABLE `property`
  ADD CONSTRAINT `property_ibfk_1` FOREIGN KEY (`intid`) REFERENCES `interiors` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT `property_ibfk_2` FOREIGN KEY (`owner`) REFERENCES `accounts` (`id`) ON DELETE SET NULL ON UPDATE CASCADE;

I can upload the full SQL file if needed.

Answer 1

Foreign key relationships involve a parent table that holds the central data values, and a child table with identical values pointing back to its parent. The FOREIGN KEY clause is specified in the child table.

It will reject any INSERT or UPDATE operation that attempts to create a foreign key value in a child table if there is no a matching candidate key value in the parent table.

To know more Go to this link

So your error Error Code: 1452. Cannot add or update a child row: a foreign key constraint fails essentially means that, you are trying to add a row to your property table for which no matching row (intid) is present in interiors table.

You must first insert the row to your interiors table.