Debian 平台下 Postgresql 数据库基本操作说明
1 安装postgresql
--使用apt 直接安装:
dave@dave:~/cndba$ sudo apt-get installpostgresql postgresql-client postgresql-server-dev-all -y
--查看数据库状态:
postgres@dave:~$ /etc/init.d/postgresql status
Running clusters: 9.1/main
--停止:
postgres@dave:~$ /etc/init.d/postgresql stop
[ ok ] Stopping PostgreSQL 9.1 databaseserver: main.
--启动:
postgres@dave:~$ /etc/init.d/postgresql start
[ ok ] Starting PostgreSQL 9.1 databaseserver: main.
postgres@dave:~$
--查看进程:
postgres@dave:~$ ps -ef|grep postgres
root 9502 9184 0 06:34 pts/2 00:00:00 su - postgres
postgres 9510 9502 0 06:34 pts/2 00:00:00 -su
postgres 9869 1 0 06:52 ? 00:00:00/usr/lib/postgresql/9.1/bin/postgres -D /var/lib/postgresql/9.1/main -cconfig_file=/etc/postgresql/9.1/main/postgresql.conf
postgres 9871 9869 0 06:52 ? 00:00:00 postgres: writer process
postgres 9872 9869 0 06:52 ? 00:00:00 postgres: wal writer process
postgres 9873 9869 0 06:52 ? 00:00:00 postgres: autovacuum launcherprocess
postgres 9874 9869 0 06:52 ? 00:00:00 postgres: stats collectorprocess
postgres 9905 9510 0 06:53 pts/2 00:00:00 ps -ef
postgres 9906 9510 0 06:53 pts/2 00:00:00 grep postgres
postgres@dave:~$
--设置开机自启动:
postgres@dave:~$ sudo update-rc.d postgresql start 88 2 3 4 5 . stop 88 0 1 6 .
update-rc.d: using dependency based bootsequencing
postgres@dave:~$
第一次安装后,默认生成一个名为postgres的数据库和一个名为postgres的数据库用户。同时还生成了一个名为postgres的Linux系统用户。
--修改postgres 用户密码:
dave@dave:~$ sudo passwd postgres
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
dave@dave:~$
2 查看数据库信息
--查看数据库信息:
dave@dave:~$ su - postgres
Password:
postgres@dave:~$ psql
psql (9.1.15)
Type "help" for help.
postgres=# help
You are using psql, the command-lineinterface to PostgreSQL.
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
postgres=#
postgres-# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+-------------+-------------+-----------------------
postgres | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
template0 | postgres | UTF8 |en_US.UTF-8 | en_US.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |=c/postgres +
| | | | |postgres=CTc/postgres
(3 rows)
postgres-#
--连接到某个数据库:
postgres-# \c postgres
You are now connected to database"postgres" as user "postgres".
postgres-# \c template1
You are now connected to database"template1" as user "postgres".
template1-#
postgres=# \c postgres
You are now connected to database"postgres" as user "postgres".
--显示当前的数据库:
postgres=# select current_database();
current_database
------------------
postgres
(1 row)
--该命令显示当前的userid:
postgres=# select current_user;
current_user
--------------
postgres
(1 row)
--退出操作界面:
template1-# \q
postgres@dave:~$
3 创建DB对象
默认的postgres用户是超级管理员,权限太大,所以一般建议创建一个独立的管理用户。
dave@dave:~$ su - postgres
Password:
postgres@dave:~$ psql
psql (9.1.15)
Type "help" for help.
--创建数据库用户、数据库,并赋予新用户新数据库的全部权限:
postgres=# create user dave with password‘dave‘;
CREATE ROLE
postgres=# create database cndba;
CREATE DATABASE
postgres=# grant all privileges on databasecndba to dave;
GRANT
postgres=#
postgres=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+-------------+-------------+-----------------------
cndba | postgres | UTF8 |en_US.UTF-8 | en_US.UTF-8 | =Tc/postgres +
| | | | | postgres=CTc/postgres+
| | | | | dave=CTc/postgres
postgres | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
template0 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |=c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |=c/postgres +
| | | | | postgres=CTc/postgres
(4 rows)
--重置postgres账户密码:
postgres=# alter user postgres withpassword ‘dave‘;
ALTER ROLE
--修改用户认证配置文件pg_hba.conf:
postgres@dave:/etc/postgresql/9.1/main$ pwd
/etc/postgresql/9.1/main
postgres@dave:/etc/postgresql/9.1/main$ ls
environment pg_ctl.conf pg_hba.conf pg_ident.conf postgresql.conf start.conf
# Database administrative login by Unixdomain socket
local all postgres trust
# TYPE DATABASE USER ADDRESS METHOD
# "local" is for Unix domainsocket connections only
local all all md5
--重新加载postgresql:
postgres@dave:/etc/postgresql/9.1/main$/etc/init.d/postgresql reload
postgres@dave:~$ psql -d cndba -U dave
Password for user dave:
psql (9.1.15)
Type "help" for help.
cndba=> selectcurrent_user;
current_user
--------------
dave
(1 row)
--表的基本操作:
postgres-> \c cndba
You are now connected to database"cndba" as user "dave".
cndba->
cndba=> create table cndba(namevarchar(20),signupdate date);
CREATE TABLE
cndba=> insert into cndba(name, signupdate)values(‘dave‘, ‘2015-02-11‘);
INSERT 0 1
cndba=> select * from cndba;
name| signupdate
------+------------
dave| 2015-02-11
(1 row)
cndba=> update cndba set name =‘tianlesoftware‘ where name = ‘dave‘;
UPDATE 1
cndba=> alter table cndba add emailvarchar(40);
ALTER TABLE
cndba=> alter table cndba alter columnsignupdate set not null;
ALTER TABLE
cndba=> alter table cndba rename columnsignupdate to signup;
ALTER TABLE
cndba=> alter table cndba drop columnemail;
ALTER TABLE
cndba=> alter table cndba rename todave;
ALTER TABLE
cndba=> drop table if exists dave;
DROP TABLE
cndba=>
4 postgresql 查看数据库,表,索引,表空间以及大小
postgres=# select pg_database.datname,pg_database_size(pg_database.datname) AS size from pg_database;
datname | size
-----------+---------
template1 | 6030136
template0 | 6030136
postgres | 6030136
cndba | 6038328
(4 rows)
--以KB,MB,GB的方式来查看数据库大小
postgres=# selectpg_size_pretty(pg_database_size(‘cndba‘));
pg_size_pretty
----------------
5897kB
(1 row)
postgres=# create table cndba(namevarchar(20),signupdate date);
CREATE TABLE
--查看多表:
postgres=# \dt
List of relations
Schema | Name | Type | Owner
--------+-------+-------+----------
public | cndba | table | postgres
(1 row)
--查看单表:
postgres=# \d cndba
Table "public.cndba"
Column | Type | Modifiers
------------+-----------------------+-----------
name | character varying(20) |
signupdate | date |
--查看表大小
postgres=# select pg_relation_size(‘cndba‘);
pg_relation_size
------------------
8192
(1 row)
--以KB,MB,GB的方式来查看表大小
postgres=# selectpg_size_pretty(pg_relation_size(‘cndba‘));
pg_size_pretty
----------------
8192bytes
(1 row)
--查看索引信息:
postgres=# create index idx_cndba oncndba(name);
CREATE INDEX
postgres=# \di
List of relations
Schema | Name | Type | Owner | Table
--------+-----------+-------+----------+-------
public | idx_cndba | index | postgres | cndba
(1 row)
--查看索引大小:
postgres=# select pg_size_pretty(pg_relation_size(‘idx_cndba‘));
pg_size_pretty
----------------
16kB
(1 row)
--看表的总大小,包括索引大小
postgres=# selectpg_size_pretty(pg_total_relation_size(‘cndba‘));
pg_size_pretty
----------------
24kB
(1 row)
--查看所有表空间:
postgres=# select spcname frompg_tablespace;
spcname
------------
pg_default
pg_global
(2 rows)
--查看表空间大小:
postgres=# selectpg_size_pretty(pg_tablespace_size(‘pg_default‘));
pg_size_pretty
----------------
23MB
(1 row)
5 PostgreSQL用户认证
PostgreSQL的配置文件在/etc/postgresql目录下:
dave@dave:/etc/postgresql/9.1/main$ pwd
/etc/postgresql/9.1/main
dave@dave:/etc/postgresql/9.1/main$ ls
environment pg_ctl.conf pg_hba.conf pg_ident.conf postgresql.conf start.conf
postgresql.conf 文件里保存的是数据库的相关的配置。
# - Connection Settings -
listen_addresses = ‘*‘ # what IP address(es) to listen on;
#comma-separated list of addresses;
#defaults to ‘localhost‘, ‘*‘ = all
#(change requires restart)
port = 5432 # (change requiresrestart)
max_connections = 100 # (change requires restart)
# Note: Increasing max_connections costs ~400 bytes of shared memory per
# connection slot, plus lock space (seemax_locks_per_transaction).
#superuser_reserved_connections = 3 # (change requires restart)
unix_socket_directory =‘/var/run/postgresql‘ # (changerequires restart)
#unix_socket_group = ‘‘ # (change requires restart)
#unix_socket_permissions = 0777 # begin with 0 to use octal notation
#(change requires restart)
#bonjour = off # advertise servervia Bonjour
#(change requires restart)
#bonjour_name = ‘‘ # defaults to thecomputer name
#(change requires restart)
注意这里的端口信息,要添加的防火墙的策略里。
pg_hba.conf中保存基于主机的认证规则。每条规则会被逐条应用,直到找到一条符合的,就能通过认证;或者访问被reject方法显式拒绝。
postgres@dave:/etc/postgresql/9.1/main$ catpg_hba.conf |grep -v ^# |grep -v ^$
local all postgres trust
local all all md5
host all all 127.0.0.1/32 md5
host all all ::1/128 md5
带注释的如下:
# Database administrative login by Unixdomain socket
local all postgres trust
# TYPE DATABASE USER ADDRESS METHOD
# "local" is for Unix domainsocket connections only
local all all md5
# IPv4 local connections:
host all all 127.0.0.1/32 md5
Type = host表示远程连接。
Database = all 表示所有数据库。
User = all 表示所有用户。
ADDRESS 由两部分组成,即IP地址/子网掩码。子网掩码规定了IP地址中前面哪些位表示网络编号。这里/0表示IP地址中没有表示网络编号的位,这样的话全部的IP地址都匹配,例如192.168.0.0/24表示匹配前24位,所以它匹配任何192.168.0.x形式的IP地址。
Method = trust 实际上表示无需认证。
--允许在本机上的任何身份连接任何数据库
TYPE DATABASE USER IP-ADDRESS IP-MASK METHOD
local all all trust(无条件进行连接)
--允许IP地址为192.168.1.x的任何主机与数据库sales连接
TYPE DATABASE USER IP-ADDRESS IP-MASK METHOD
host sales all 192.168.1.0 255.255.255.0 identsameuser
6 远程访问数据库
postgresql默认情况下,远程访问不能成功,如果需要允许远程访问,需要修改两个配置文件,说明如下:
(1)postgresql.conf
将该文件中的listen_addresses项值设定为*。
(2)pg_hba.conf
在该配置文件的host allall 127.0.0.1/32 md5行下添加以下配置,或者直接将这一行修改为以下配置
host all all 0.0.0.0/0 md5
表示允许所有IP访问。
修改之后,Reload 或者重启数据库让修改生效:
postgres@dave:/etc/postgresql/9.1/main$/etc/init.d/postgresql reload
直接使用Navicat 链接:
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