php-libinnodb-fk

This library retrievies and optionally resolves foreign keys in a MySQL/MariaDB database using the InnoDB storage engine.

This library will only work with databases created with InnoDB

Install with composer

composer require victorwesterlund/innodb-fk

use victorwesterlund\ForeignKeys

Example / Documentation

Start by initializing ForeignKeys with mysqli connection details. ForeignKeys will pass the arguments along to mysqli::__construct().

Remember to pass the database name where InnoDB foreign keys are stored to the 4th argument. The user must also have SELECT permissions on this database as the (4th) $database argument. It's usually information_schema. You can also pass the ForeignKeys::DATABASE_NAME constant if you're unsure.

Example database relationship:

Initialize `ForeignKeys`

use victorwesterlund\ForeignKeys

$fk = new ForeignKeys($host, $user, $pass, ForeignKeys::DATABASE_NAME);

Get column constraints for a table

Pass a database and table to for() and then chain get_constraints() to receive an associative array of all column relationships for that table.

$fk->for("test", "bar")->get_constraints();

[
   // Name of the column that has a foreign key reference
   "fk" => [
      // key is the database and table it references. Value is the column
      "test.foo" => "id"
   ]
]

Resolve foreign key references for entities

You can also resolve foreign key references for a passed array of arrays.

Retrieve rows from your database and pass them to resolve_all() as an array of associatve arrays to resolve them automatically.

$rows = [
   [
      "id" => 1,
      "fk" => 2
   ],
   [
      "id" => 2,
      "fk" => 1
   ]
];

$rows = $fk->for("test", "bar")->resolve_all($rows);

// $rows will become
[
   [
      "id" => 1,
      "fk" => [
         "id"    => 2,
         "value" => "lorem ipsum dolor sit amet"
      ]
   ],
   [
      "id" => 2,
      "fk" => [
         "id"    => 1,
         "value" => "consectetur adipiscing elit"
      ]
   ]
]