Rich Shepard <rshepard(at)appl-ecosys(dot)com> writes:
> I want to copy query results to a text file and there's an aggregate
> function in the SELECT expression. One of the aggregate function's
> parentheses seems to end the \copy() function and I don't know how best to
> write the statement. A minimal example:
> \copy(select count_value, sum(count_value)
> from table_name) to 'output_file.txt';
I think your problem is the line break, not the parentheses.
psql knows how to count parens, but it has no concept of letting
backslash commands continue across lines.
regards, tom lane