Write SQL query to solve given problem: How many units of item no.9 were sold in store no.1 in total in January, 2012?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT SUM(units) FROM sales_in_weather WHERE SUBSTR(`date`, 6, 2) = '01' AND SUBSTR(`date`, 1, 4) = '2012' AND item_nbr = 9 AND store_nbr = 1