Re: The same prepared query yield "-1" the first six times and then "-1.0"

Use the type appropriate getter, not getString, to retrieve the value of the underlying real typed column.

I know, but in this occasion I need to use text value.

Otherwise, I agree this seems like a bug, probably in the JDBC driver, though one pertains to style as opposed to semantics since both answers are technically correct.

I will try, thank you

Edoardo

You appear to have two code paths in your application.  The one that needs the string version of the answer should do the conversion of the numeric value.
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