How to count households from each postcode in the database <p>I made an er diagram for a business and based on which I need to run a query for counting household from each postcode. </p> <pre><code>SELECT CU.POSTCODE, Count(CU.CUSTOMER_ID) AS HOUSEHOLDS_PER_POSTCODE FROM CUSTOMER AS CU INNER JOIN HOUSEHOLD AS HHD ON CU.CUSTOMER_ID = HHD.CUSTOMER_ID GROUP BY CU.POSTCODE; </code></pre> <p>Is this a good way? </p>