NOTE: From my research online, I found that typecasting works and also the error from the database suggests typecasting.
This statement works:
UPDATE t_update SET F1 = (CASE WHEN (?::timestamp(6) IS NULL ) THEN (?::timestamp(6) ) ELSE (?::timestamp(6) ) END)
There is no option to convert the text parameter to a timestamp - you need to cast it - or use a parsing function or something else - but a text value cannot drop directly into a timestamp column. But it's not the case statement that is the issue - but rather the update - so you could shorten the statement a little with this.
UPDATE t_update SET F1 = (CASE WHEN (? IS NULL ) THEN (?) ) ELSE (?) ) END)::timestamp(6)
You don't need a timestamp until you place in in the column.
You also probably don't want a case statement here - not the standard option for this
UPDATE t_update SET F1 = COALESCE(?, ?)::timestamp(6) with the first ? being the when above and the second being the else above. See here [1]
