The insert statement is used to populate a class with instances:
INSERT INTO weather
VALUES ('San Francisco', 46, 50, 0.25, '11/27/1994')
You can also use the copy command to perform load large amounts of data from flat (ASCII) files. This is usually faster because the data is read (or written) as a single atomic transaction directly to or from the target table. An example would be:
COPY INTO weather FROM '/home/user/weather.txt'
USING DELIMITERS '|';
where the path name for the source file must be available to the backend server machine, not just the client.
Read the upstream documentation. For corrections, first check the current manual.