Shulou(Shulou.com)06/01 Report--

Installation

1 add source

Sudo rpm-Uvh https://download.postgresql.org/pub/repos/yum/9.4/redhat/rhel-6-x86_64/pgdg-centos94-9.4-3.noarch.rpm

2 installation

Sudo yum install postgresql94-server postgresql94-contrib

3 verify that the installation is successful

Sudo rpm-aq | grep postgres

The following results should occur

Postgresql94-libs-9.4.6-1PGDG.rhel6.x86_64

Postgresql94-server-9.4.6-1PGDG.rhel6.x86_64

Postgresql94-9.4.6-1PGDG.rhel6.x86_64

Postgresql94-contrib-9.4.6-1PGDG.rhel6.x86_64

4 switch to the postgres account, initialize and start the database

Su postgres

/ usr/pgsql-9.4/bin/initdb-pgdata=/data/postgres-locale=C-encoding=utf8

/ usr/pgsql-9.4/bin/pg_ctl-D / data/postgres-l / data/postgres/psotgres.log start

2.5 use psql to connect to the database (non-postgres users can be used)

Psql-U postgres

Library operation

\ h: check the explanation of the SQL command, such as\ h select.

\?: view a list of psql commands.

\ l: list all databases.

\ C [database_name]: connect to other databases.

\ d: lists all tables for the current database.

\ d [table_name]: lists the structure of a table.

\ du: list all users.

\ e: open a text editor.

\ conninfo: lists the current database and connection information.

Log into the database

Psql-U postgres-W (password)-h 127.0.0.1

Create a database

Create database databa_name

Backup database

Pg_dump-h 127.0.0.1-U postgres databasename > / data/backup_name.sql

Import database

Psql-h localhost-U postgres-d databasename < / data/backup_name.sql

Modify database password

ALTER USER postgres WITH PASSWORD 'postgres'

Table operation

Create a new table

CREATE TABLE user_tbl (name VARCHAR (20), signup_date DATE)

Insert data

INSERT INTO user_tbl (name, signup_date) VALUES ('Zhang San', '2013-12-22')

Select record

SELECT * FROM user_tbl

Update data

UPDATE user_tbl set name ='Li Si 'WHERE name =' Zhang San'

Delete record

DELETE FROM user_tbl WHERE name ='Li Si'

Add a field

ALTER TABLE user_tbl ADD email VARCHAR (40)

Update structure

ALTER TABLE user_tbl ALTER COLUMN signup_date SET NOT NULL

Rename field

ALTER TABLE user_tbl RENAME COLUMN signup_date TO signup

Delete a field

ALTER TABLE user_tbl DROP COLUMN email

Rename the form

ALTER TABLE user_tbl RENAME TO backup_tbl

Delete form

DROP TABLE IF EXISTS backup_tbl

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