How to update PostgreSQL on Ubuntu

You can run the update statement (the condition of update is the judgment condition that exists), and then call get diagnostics to obtain the number of rows affected by the execution of the previous SQL statement.

Structure is similar: declare

v_cnt integer;

beginupdate ..Execute the update statement where ...The condition here is the judgment condition that exists: get diagnostics v cnt = row count; - Assign a value that affects the number of rows to v cnt

if v_cnt = 0 then

insert into ..Execute the insert statement end if;

end;

Install the PostgreSQL database server on the Ubuntu system.

Step 1: Add the APT repository for PostgreSQL.

The PostgreSQL package is also found in the Ubuntu default repository, but when I try to install PostgreSQL in Ubuntu I only find PostgreSQL in the default apt repository. So, I ask you to first add the postgresql apt repository on your system to the official postgresql recommendation** to use the following command.

Step 2: Install PostgreSQL

Now that we have added the official postgresql repository to our system, first we need to update the list of repositories. We have installed the latest PostgreSQL server on our ubuntu system using the following command.

sudo apt-get update

sudo apt-get install postgresql postgresql-contrib

Step 3: Connect to PostgreSQL

After installing the postgreSQL database server, by default, it creates a user of postgres with the role "postgres". It also creates a "postgres" system account with the same name. So, to connect to the server postgres, log in to the system user postgres and connect to the database.

sudo su - postgres

psql now you log in to the postgresql database server. The login information to be checked is used after the command is sent from the database command prompt.

postgres-# conninfo

To disconnect from the postgresql database command prompt, simply type the following command and press enter. It will reward you back to the Ubuntu command prompt.

postgres-# q

Your PostgreSQL installation has completed successfully. Let's take a look at phppgadmin installed on Ubuntu system.

Install PostgreSQL

sudo apt-get update

sudo apt-get install postgresql postgresql-contrib1212

Uninstall PostgreSQL

Completely remove postgresql by running the following command (note that important data is backed up in advance).

sudo apt-get purge 'postgresql-*'

sudo apt-get autoremove 'postgresql-*'

On Linux that has PostgreSQL installed, run the following command to query the installed version:

psql --version

PostgreSQL is a version-based object-relational database management system (OORDBMS) developed by the Department of Computer Science at the University of California, Berkeley, and is now renamed PostgreSQL. PostgreSQL supports most of the SQL standards and provides many other modern features: complex queries, foreign keys, triggers, views, transaction integrity, MVCC.

Similarly, PostgreSQL can be extended in many ways, for example, by adding new data types, functions, operators, aggregate functions, and indexes. It's free to use, modify, and distribute PostgreSQL for private, commercial, or academic research use.

Version: psql --version

Uninstall: Don't know how you installed it? I've only installed on ubuntu. After adding the source, you can call apt for both installation and uninstallation.

Start by looking for the one generated by postgresql. In **, you can use the find command to find it, which is generally generated in.

tmp directory, or other directories.

Modify the user profile.

Add to. export pghost= tmp is where you find the directory. The directory where the file is located.

Or when using the psql command, use the -h parameter to specify the directory where it is located, and when using this method, you may need to modify the postgersql configuration file to change the path of the Unix socket.

The reason for this problem is that the path to the unix socket is compiled in the program file, and you can also modify the source of postgresql to solve this problem.

I'm going to delete everything from postgresql first, and then **postgresql.run file installation,It's exactly the same as installing it under win7,The path is according to the default when installing。