Update Biggest Single number.sql

[SyedaFarhath]

I am a beginner learning PostgreSQL so I tried this alternate solution just a minute change.

Following your repos really helpful Thankyou.

[pratik221b]

is this correct ?

SELECT TRANSACTION_COUNT, COUNT(VISIT_DATE) AS VISITS_COUNT
FROM
(

SELECT A.USER_ID, A.VISIT_DATE, SUM( CASE WHEN B.TRANSACTION_DATE IS NULL THEN 0 ELSE 1 ) AS TRANSACTIONS_COUNT
FROM VISITS A LEFT JOIN TRANSACTIONS B ON A.USER_ID=B.USER_ID AND A.VISIT_DATE=B.TRANSACTION_DATE
GROUP BY 1,2

)
GROUP BY 1