COALESCE two dates returns binary?

Question

Why does COALESCE(date1,date2) return Blob(binary)? Both columns are of type DATETIME.

Here\'s the complete sql query:

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Answer 1

I still don't know why this happens in MySql Workbench (and also MS Visual Studio). But i have found a workaround. I just cast the result to DATETIME and it works as expected:

SELECT CAST(COALESCE( last_modified, date_purchased )AS DATETIME)As LastModifiedOrPurchased
FROM Orders
ORDER BY COALESCE( last_modified, date_purchased )DESC
LIMIT 1;

Edit: as Jack has commented, IFNULL works also:

SELECT IFNULL( last_modified, date_purchased )As LastModifiedOrPurchased
FROM Orders
ORDER BY IFNULL( last_modified, date_purchased )DESC
LIMIT 1;