红色部分的三条命令完成把结果集输出到文件!!
[root@test root]# psql -hlocalhost -Utest test
Welcome to psql 8.0.3, the PostgreSQL interactive terminal.
Type: \copyright for distribution terms
\h for help with SQL commands
\? for help with psql commands
\g or terminate with semicolon to execute query
\q to quit
gudumami=# \f ,
Field separator is ",".
gudumami=# \o /tmp/test.csv
gudumami=# SELECT * WHERE test ORDER BY id;
gudumami=# \q