How to check if there are maximal values in both SQL tables?-CodePudding

I apologize for the maybe stupid question. But I can't get a handle on it.

My postgres database has two tables with report dates. How can I check if the last report dates are the same?

I have tried:

select max (report_date)
from tba900_rephistory;
      CASE
        WHEN EXISTS (select max(reportdate) from t_data
          THEN 'EXISTS'
        ELSE 'missing'
      END

But, it works every once in a while. SQL is not my strong suit, but I couldn't find anything to google.

In fact, I do it through psycopg2 in python. Maybe there are some tricks?

CodePudding user response：

You may use this query:

SELECT CASE WHEN (SELECT MAX(report_date) FROM tba900_rephistory) =
                 (SELECT MAX(reportdate) FROM t_data)
            THEN 'exists' ELSE 'missing' END AS status;