PostgreSQL中，database,schema,table之间关系

从逻辑上看，schema，table，都是位于database之下。

首先，在postgres数据库下建立表(相当于建立在public schema下)：

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

postgres=# create table tab200(id integer);
CREATE TABLE
postgres=# \q

然后，再在tester数据库下建立表(相当于建立在public schema下)：

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

tester=# create table tab200(id integer);
CREATE TABLE
tester=# \q

然后，再在其他的数据库下进行查看：

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

pgsql=# SELECT * FROM information_schema.tables WHERE table_name='tab200';
 table_catalog | table_schema | table_name | table_type | self_referencing_column_name | reference_generation | user_de
fined_type_catalog | user_defined_type_schema | user_defined_type_name | is_insertable_into | is_typed | commit_action
---------------+--------------+------------+------------+------------------------------+----------------------+--------
-------------------+--------------------------+------------------------+--------------------+----------+---------------
(0 rows)

pgsql=# \q

然后，再在 postgres数据库和tester数据库下分别查看：

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

tester=# SELECT * FROM information_schema.tables WHERE table_name='tab200';
 table_catalog | table_schema | table_name | table_type | self_referencing_column_name | reference_generation | user_de
fined_type_catalog | user_defined_type_schema | user_defined_type_name | is_insertable_into | is_typed | commit_action
---------------+--------------+------------+------------+------------------------------+----------------------+--------
-------------------+--------------------------+------------------------+--------------------+----------+---------------
 tester        | public       | tab200     | BASE TABLE |                              |                      |
                   |                          |                        | YES                | NO       |
(1 row)

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

postgres=# SELECT * FROM information_schema.tables WHERE table_name='tab200';
 table_catalog | table_schema | table_name | table_type | self_referencing_column_name | reference_generation | user_de
fined_type_catalog | user_defined_type_schema | user_defined_type_name | is_insertable_into | is_typed | commit_action
---------------+--------------+------------+------------+------------------------------+----------------------+--------
-------------------+--------------------------+------------------------+--------------------+----------+---------------
 postgres      | public       | tab200     | BASE TABLE |                              |                      |
                   |                          |                        | YES                | NO       |
(1 row)