src/Phinx/Db/Table.php
public function hasForeignKey($columns, $constraint = null)
    {
        return $this->getAdapter()->hasForeignKey($this->getName(), $columns, $constraint);
    }
public function hasForeignKey($columns, $constraint = null)
    {
        return $this->getAdapter()->hasForeignKey($this->getName(), $columns, $constraint);
    }
public function hasForeignKey ( $ columns , $ constraint = null ) { return $ this -> getAdapter ( ) -> hasForeignKey ( $ this -> getName ( ) , $ columns , $ constraint ) ; }
Checks to see if a foreign key exists.

@param  string|array $columns    Column(s)
@param  null|string  $constraint Constraint names
@return bool
Checks to see if a foreign key exists .