timestamp in c++

I try to extract timestamp column from query using getString method of object ResultSet. Unfortunetly Tihs method fails (in documentation stands that this method returns column AS string - not only char column I think). So I tried getTimestamp() and it worked. But it returns Timestamp object. I need to convert value of this object to string using toText method. But I cannot find syntax of fmt parameter of this method. Please help.

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Marcin Wójtowski
mwojtow_at_dmcs.p.lodz.pl