system/Database/BaseConnection.php
public function table($tableName)
	{
		if (empty($tableName))
		{
			throw new DatabaseException('You must set the database table to be used with your query.');
		}

		$className = str_replace('Connection', 'Builder', get_class($this));

		return new $className($tableName, $this);
	}
public function table($tableName)
	{
		if (empty($tableName))
		{
			throw new DatabaseException('You must set the database table to be used with your query.');
		}

		$className = str_replace('Connection', 'Builder', get_class($this));

		return new $className($tableName, $this);
	}
Returns an instance of the query builder for this connection.

@param string|array $tableName

@return BaseBuilder
@throws DatabaseException