src/Db/Migration.php
public function dropForeignKey($name, $table)
    {
        $cmdPromise = $this->createCommand()->dropForeignKey($name, $table)->execute();
        return $this->execPromise($cmdPromise, "drop foreign key $name from table $table");
    }
public function dropForeignKey($name, $table)
    {
        $cmdPromise = $this->createCommand()->dropForeignKey($name, $table)->execute();
        return $this->execPromise($cmdPromise, "drop foreign key $name from table $table");
    }
Builds a SQL statement for dropping a foreign key constraint.
@param string $name the name of the foreign key constraint to be dropped. The name will be properly quoted by the method.
@param string $table the table whose foreign is to be dropped. The name will be properly quoted by the method.
@return LazyPromiseInterface