PostgreSQL中如何查询在当前的哪个数据库中

[pgsql@localhost bin]$ ./psql -d tester
psql (9.1.2)
Type "help" for help.

tester=# select current_database();
 current_database 
------------------
 tester
(1 row)

tester=# 

 http://www.postgresql.org/docs/7.3/static/functions-misc.html