Linux roblaptop 4.9.0-1-amd64 #1 SMP Debian 4.9.2-2 (2017-01-12) x86_64 GNU/Linux
I was running a query like:-
SELECT TO_CHAR(my_date,'dd-mm-yyyy) FROM my_table;
and I forgot to type the second single quotation mark at the end of the mask string.
Under psql it just hung and I had to Ctrl-C to go back to a prompt and under JDBC it hung as well and EQ just said "error", as in a failure of some sort.
I would have expected either a 42601 error or maybe a 03000 error to have been returned.
At least in psql that isn't a query. It's a multi-line query fragment. The UI is waiting for you to enter more of the query and end the string literal that you've begun.
Also, that is indicated by the change in prompt from => to '> (assuming you are using the default prompts).
That would seem to be bug in JDBC, though. Rob, can you provide a full example code?