要创建一个数据库，必须是一个超级用户或者具有特殊的CREATEDB特权，默认情况下，新数据库将通过克隆标准系统数据库template1被创建。可以通过写TEMPLATE name指定一个不同的模板。特别地，通过写TEMPLATE template0您可以创建一个干净的数据库，它将只包含的Teledb所预定义的标准对象。
默认参数创建数据库
teledb=# create database teledb_db;
CREATE DATABASE指定克隆库
teledb=# create database teledb_db_template TEMPLATE template0;
CREATE DATABASE指定所有者
teledb=# create role teledb_user with login;
CREATE ROLE
teledb=# create database teledb_db_owner owner teledb_user;
CREATE DATABASE
teledb=# \l+ teledb_db_owner
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges | Size | Tablespace | Description
------------------+--------------+----------+-------------+-------------+-------------------+-------+------------+-------------
teledb_db_owner | teledb_user | UTF8 | zh_CN.UTF-8 | zh_CN.UTF-8 | | 19 MB | pg_default |
(1 row)指定编码
teledb=# create database teledb_db_encoding ENCODING UTF8;
CREATE DATABASE
teledb=# \l+ teledb_db_encoding
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges | Size | Tablespace | Description
---------------------+---------+----------+-------------+-------------+-------------------+-------+------------+-------------
teledb_db_encoding | teledb | UTF8 | zh_CN.UTF-8 | zh_CN.UTF-8 | | 19 MB | pg_default |
(1 row)创建gbk编码
teledb=# CREATE DATABASE db_gbk template template0 encoding = gbk LC_COLLATE = 'zh_CN.gbk' LC_CTYPE = 'zh_CN.gbk';
CREATE DATABASE
teledb=# \d db_gbk
Did not find any relation named "db_gbk".
teledb=# \l+ db_gbk
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges | Size | Tablespace | Description
--------+---------+----------+-----------+-----------+-------------------+-------+------------+-------------
db_gbk | teledb | GBK | zh_CN.gbk | zh_CN.gbk | | 19 MB | pg_default |
(1 row)指定排序规则
teledb=# create database teledb_db_lc_collate lc_collate 'C' template template0;
CREATE DATABASE指定分组规则
teledb=# create database teledb_lc_ctype LC_CTYPE 'C' template template0;
CREATE DATABASE配置数据可连接
teledb=# create database teledb__allow_connections ALLOW_CONNECTIONS true;
CREATE DATABASE
teledb=# select datallowconn from pg_database where datname = 'teledb__allow_connections';
datallowconn
--------------
t
(1 row)
teledb=# \c teledb__allow_connections
You are now connected to database "teledb__allow_connections" as user "teledb".配置连接数
teledb=# create database teledb_connlimit CONNECTION LIMIT 100;
CREATE DATABASE
teledb=# select datconnlimit from pg_database where datname='teledb_connlimit';
datconnlimit
--------------
100
(1 row)配置数据库可以被复制（是否模板数据库）
teledb=# create database teledb_istemplate is_template true;
CREATE DATABASE
teledb=# select datconnlimit from pg_database where datname='teledb_connlimit';
datconnlimit
--------------
100
(1 row)多个参数一起配置
teledb=# create database teledb_mul owner teledb_user CONNECTION LIMIT 50 template template0 encoding 'utf8' lc_collate 'C';
CREATE DATABASE
