“SQL obtient la date la plus élevée à partir de 3 tabels” Réponses codées

SQL obtient la date la plus élevée à partir de 3 tabels

SELECT MAX(MaxDate) FROM (SELECT MAX(TradeDate) AS MaxDate FROM Office.Transactions WHERE BrokerID = 1 AND TradeDate IS NOT NULLUNIONSELECT MAX(EntryDate) AS MaxDate FROM Office.IOI WHERE BrokerID = 1UNIONSELECT MAX(EntryDate) AS MaxDate FROM Office.TradeNotes WHERE BrokerID = 1) AS X