/**
* Returns true if at least one of the local columns of $fk is not already covered by another
* foreignKey in our collection (getCrossForeignKeys)
*
* E.g.
*
* table (local primary keys -> foreignKey):
*
* pk1 -> FK1
* pk2
* \
* -> FK2
* /
* pk3 -> FK3
* \
* -> FK4
* /
* pk4
*
* => FK1(pk1), FK2(pk2, pk3), FK3(pk3), FK4(pk3, pk4).
*
* isAtLeastOneLocalPrimaryKeyNotCovered(FK1) where none fks in our collection: true
* isAtLeastOneLocalPrimaryKeyNotCovered(FK2) where FK1 is in our collection: true
* isAtLeastOneLocalPrimaryKeyNotCovered(FK3) where FK1,FK2 is in our collection: false
* isAtLeastOneLocalPrimaryKeyNotCovered(FK4) where FK1,FK2 is in our collection: true
*
* @param ForeignKey $fk
* @return bool
*/
public function isAtLeastOneLocalPrimaryKeyNotCovered(ForeignKey $fk)
{
$primaryKeys = $fk->getLocalPrimaryKeys();
foreach ($primaryKeys as $primaryKey) {
$covered = false;
foreach ($this->getCrossForeignKeys() as $crossFK) {
if ($crossFK->hasLocalColumn($primaryKey)) {
$covered = true;
break;
}
}
//at least one is not covered, so return true
if (!$covered) {
return true;
}
}
return false;
}