PostgreSQL

Often encounter an application scenario that summarizes, compares, and sorts the contents of some rows.such as the data table name Test.test2Select from Test.test2Get results:1828;"Heilongjiang"137;"Heilongjiang"184;"Heilongjiang"183;"Fujian"

I. Establishment of the tablelihao= #create table TB (ID int,pid int,name varchar); lihao= #INSERT into TB VALUES (1, 0, ' Guangdong Province '); lihao= #INSERT into TB VALUES (2, 0, ' Zhejiang Province '); lihao= #INSERT into TB VALUES (3, 2, '

Pg_hba.conf is a client authentication configuration fileMETHOD specifies how the client's authentication is handled. Commonly used are ident,md5,password,trust,reject.PostgreSQL only listens to local ports by default, and Netstat-tuln only sees

Using the Iostat command to find that the IO usage of a disk is often maintained at 100%, after acquiring the relationship between the Linux RAID storage drive letter and the mount point through the Blkid command, it is finally discovered that a

1Before you install PostgreSQL, verify that the Internet connection is working to download the installation files. Use Yum First-y update instructions to upgrade the system to the latest version. 2. Turn off Firewall service: #/etc/init.d/iptables

In PostgreSQL everyone has used round bar, how to show when the decimal point? See Example SELECT To_char (Round (127 * 0.1/67543,6) *10000, ' 90.99 ') 1.88 SELECT To_char (Round (127 * 0.1/67543,6) *10000, ' 90.00 ') 1.88 SELECT To_char (Round (

High availability, Load balancing, and Replication Feature Matrix Feature Shared Disk Failover File System Replication hot/warm Standby Using PITR trigger-based Master-standby Replication statement-based

Recently to use PostgreSQL under Linux, search the Internet for information, to organize the installation and configuration of PostgreSQL-9.3First step: Installing PostgreSQLsudo apt-get install postgresql-9.3Step Two: Configure the password for the

Here I would like to demonstrate how to achieve the cross-table in PostgreSQL display, as to what is a cross-table, I will not say, the degree Niang go oh.The original table data is as follows:t_girl=# select * from score; name  | subject | score - -

PostgreSQL function is huge, to achieve multiplication this kind of operation has many methods, today I will briefly enumerate the following several convenient ways.Like we're counting 10!1, you can use SQL to expand it:t_girl=# Select 1*2*3*4*5*6*7*

This code recipe gives the idea of what you have to use Flask-admin with PostgreSQL database.From flask import flaskfrom flask.ext.admin import adminfrom flask.ext.admin import baseviewfrom flask.ext.admin import ex Posefrom flask.ext.sqlalchemy

: Http://www.enterprisedb.com/products-services-training/pgdownload Select the appropriate version (QQ1033163112 download encounters a problem q me)The basic is the next step you can use to remember the password when you set the passwordConsole runs

PostgreSQL provides services using the client/server (c/s) mode, where a PostgreSQL session consists of the following related processes (Programs):(1) A server-side process. The process manages the database files, accepts the client's connection to

Here, my system is Ubuntu14.04 LTS. Installing RVM and RubyRun: Curl-ssl Https://get.rvm.io | Bash-s Stable--rubyIf no curl is installed, command: sudo apt-get install curl Installing RailsRunning: sudo gem install rails Installing

Https://wiki.postgresql.org/wiki/Aptsudo nano/etc/apt/sources.list.d/pgdg.list Paste Deb http://apt.postgresql.org/pub/repos/apt/ precise-pgdg mainctrl+o return ctrl+x wget--quiet-o-HTTPS://WWW.POSTGRESQL.ORG/MEDIA/KEYS/ACCC4CF8.ASC | sudo

You do not need to enter the password for local backup: Pg_dump -- Host 10.13.38.81 -- username "s" -- no-Password -- format tar -- blobs -- verbose -- file "D: \ pg. Bak" "mydb"   You need to manually enter the password for backup on a different

Original article: http://www.cnblogs.com/xinyaping/archive/2011/04/15/2089081.html Environment: Ubuntu 12.04 + PostgreSQL 9.1 PostgreSQL is installed by default using the dpkg-I command. The file paths of other installation methods may be

In North America, people are enthusiastic about PostgreSQL. With the development of postgresql, PostgreSQL 8.x has already surpassed MySQL 5.x technically, and market transcendence is only a matter of time. In the end, users may have the opportunity

In the past two days, due to project reasons, I had a little bit of confidence and learned how to embed SQL into PostgreSQL in C. I wrote a small example, including connecting to the database and creating tables, for more information, see PostgreSQL8

XML content generationSQL data generation XML function.1. xmlcomment: generate the annotation function. Xmlcomment (text)Example: SELECT xmlcomment ('hello ');Xmlcomment-------------- 2. xmlconcat: XML connection Function Xmlconcat (xml