system/Database/Forge.php
public function addKey($key, bool $primary = false, bool $unique = false)
	{
		if ($primary === true)
		{
			foreach ((array)$key as $one)
			{
				$this->primaryKeys[] = $one;
			}
		}
		else
		{
			$this->keys[] = $key;
			if ($unique === true)
			{
				$this->uniqueKeys[] = ($c = count($this->keys)) ? $c - 1 : 0;
			}
		}

		return $this;
	}
public function addKey($key, bool $primary = false, bool $unique = false)
	{
		if ($primary === true)
		{
			foreach ((array)$key as $one)
			{
				$this->primaryKeys[] = $one;
			}
		}
		else
		{
			$this->keys[] = $key;
			if ($unique === true)
			{
				$this->uniqueKeys[] = ($c = count($this->keys)) ? $c - 1 : 0;
			}
		}

		return $this;
	}
Add Key

@param string|array $key
@param boolean      $primary
@param boolean      $unique

@return Forge