You’ve installed PostgreSQL. Now what? I assume you’ve been given a task that uses
psql
and you want to learn the absolute minimum toget the job done.- Postgresql Online Practice
- Postgresql Online Tester
- Postgresql Online Ide
- Postgresql Org Download
- Compile Postgresql Online
This is both a brief tutorial and a quick reference for the absolute least you need to know about
psql
. I assume you’re familiar with the command line and have a rough idea aboutwhat database administration tasks, but aren’t familiar with how touse psql
to do the basics.Known issues and limitations associated with online migrations from PostgreSQL to Azure Database for PostgreSQL are described in the following sections. Online migration configuration. The source PostgreSQL server must be running version 9.4, 9.5, 9.6, 10, or 11. For more information, see the article Supported PostgreSQL Database Versions. Fully Managed HA PostgreSQL. ElephantSQL automates every part of setup and running of PostgreSQL clusters. Available on all major cloud and application platforms all over the world. Let your team focus on what they do best - building your product. Leave server management and monitoring to the experts. Interactive Course. SQL Practice Set in PostgreSQL. This online practice set consists of 88 interactive exercises. You will practice using simple statements and clauses, like SELECT or JOIN, as well as more advanced concepts, such as subqueries. Compile postgresql online Language: Ada Assembly Bash C# C (gcc) C (clang) C (vc) C (gcc) C (clang) C (vc) Client Side Clojure Common Lisp D Elixir Erlang F# Fortran Go Haskell Java Javascript Kotlin Lua MySql Node.js Ocaml Octave Objective-C Oracle Pascal Perl Php PostgreSQL Prolog Python Python 3 R Rust Ruby Scala Scheme Sql Server. Compile postgresql online Language: Ada Assembly Bash C# C (gcc) C (clang) C (vc) C (gcc) C (clang) C (vc) Client Side Clojure Common Lisp D Elixir Erlang F# Fortran Go Haskell Java Javascript Kotlin Lua MySql Node.js Ocaml Octave Objective-C Oracle Pascal Perl Php PostgreSQL Prolog Python Python 3 R Rust Ruby Scala Scheme Sql Server.
The PostgreSQL documentation is incredibly well written and thorough, but frankly, I didn’t know where to start reading. Thisis my answer to that problem.
If you have any complaints or suggestions please let me know by sending your feedback to [email protected].
It shows how to do the following at the
psql
prompt:- Reference pointing to the official PostgreSQL documentation
If you don’t have access to a live PostgreSQL installation at the moment we still have your back.You can follow through the examples and the output is shown as if youdid type everything out.
The psql command line utility
Many administrative tasks can or should be done on your local machine, even though if database lives on the cloud.You can do some of them through a visual user interface, but that’s not covered here. Knowing how to perform these operations on the command line means you can script them,and scripting means you can automate tests, check errors, and do data entry on the command line.
This section isn’t a full cheat sheet for
psql
.It covers the most common operations and shows them roughly in sequence, as you’d use them in a typical work session.Starting and quitting the psql interactive terminal |
---|
Command-line prompts for psql |
Quitting psql |
Opening a connection locally |
Opening a connection remotely |
Looking at the psql prompt |
Getting information about databases |
h Help |
l List databases |
c Connect to a database |
dt Display tables |
d and d+ Display columns (field names) of a table |
du Display user roles |
Creating and using tables and records |
Creating a database |
Creating a table (CREATE TABLE) |
Adding a record (INSERT INTO) |
Inserting several records at once (INSERT INTO) |
Adding only specific fields from a record |
Doing a simple query–get a list of records (SELECT) |
Maintenance and operations |
Maintenance |
What you need to know
Before using this section, you’ll need:
- The user name and password for your PostgreSQL database
- The IP address of your remote instance
Command-line prompts on the operating system
The
$
starting a command line in the examples below represents your operating system prompt. Prompts are configurable so it may well not look like this. On Windows it might look like C:Program FilesPostgreSQL>
but Windows prompts are also configurable.A line starting with
#
represents a comment. Same for everything to the right of a #
. If you accidentally type it or copy and paste it in, don’t worry. Barcode 1 5 – professional barcode generation software. Nothing will happen.Using psql
You’ll use
psql
(aka the PostgreSQL interactive terminal) most of all because it’s used to create databases and tables, show information about tables, and even to enter information (records) into the database.Quitting pqsql
Before we learn anything else, here’s how to quit
psql
and return to the operating system prompt.You type backslash, the letter q
, and then you press the Enter or return key.This takes you back out to the operating system prompt.
Opening a connection locally
A common case during development is opening a connection to a local database (one on your own machine).Run
psql
with -U
(for user name) followed by the name of the database, postgres
in this example:Opening a connection remotely
To connect your remote PostgreSQL instance from your local machine, use
psql
at your operating system command line.Here’s a typical connection.Here you’d enter the password. In case someone is peering over your shoulder, the characters are hidden. After you’ve entered your information properly you’ll get this message (truncated for clarity):
Looking at the psql prompt
A few things appear, then the
psql
prompt is displayed.The name of the current database appears before the prmopt.At this point you’re expected to type commands and parameters into the command line.
psql vs SQL commands
psql
has two different kinds of commands. Those starting with a backslashare for psql
itself, as illustrated by the use of q
to quit.Those starting with valid SQL are of course interactive SQL used tocreate and modify PostgreSQL databases.
Warning: SQL commands end with a semicolon!
One gotcha is that almost all SQL commands you enter into
psql
must end in a semicolon.- For example,suppose you want to remove a table named
sample_property_5
. You’d enter this command:
It’s easy to forget. If you do forget the semicolon, you’ll see this perplexing prompt.Note that a
[
has been inserted before the username portion of the prompt, and anotherprompt appears below it:When you do, just remember to finish it off with that semicolon:
Getting information about databases
These aren’t SQL commands so just press Enter after them. Remember that:
- When there’s more output than fits the screen, it pauses. Press space to continue
- If you want to halt the output, press
q
.
h Help
You’ll get a long list of commands, then output is paused:
- Press space to continue, or
q
to stop the output.
You can get help on a particular item by listing it after the
h
command.- For example, to get help on
DROP TABLE
:
You’ll get help on just tha item:
l List databases
What most people think of as a database (say, a list of customers) is actually a table. A database is a set of tables, information about those tables, information about users and their permissions, and much more. Some of these databases (and the tables within) are updated automatically by PostgreSQL as you use them.
To get a list of all databases:
You can get info on a single database by following the
l
prompt with its name.- For example, to view information about the
template0
database:
The output would be:
l+ List databases with size, tablespace, and description
To get additional information on the space consumed by database tablesand comments describing those tables, use
l+
:c Connect to a database
To see what’s inside a database, connect to it using
c
followed by the database name. The prompt changes to match the name of the database you’re connecting to.(The one named postgres
is always interesting.) Here we’re connecting to the one namedmarkets
:dt Display tables
- Use
dt
to list all the tables (technically, relations) in the database:
- If you choose a database such as
postgres
there could be many tables.Remember you can pause output by pressing space or halt it by pressingq
.
d and d+ Display columns (field names) of a table
To view the schema of a table, use
d
followed by the name of the table.- To view the schema of a table named
customerpaymentsummary
, enter
To view more detailed information on a table, use
d+
:du Display user roles
- To view all users and their roles, use
du
:
- To view the role of a specific user, pass it after the
du
command.For example, to see the onlytom
role:
Creating a database
Before you add tables, you need to create a database to contain those tables.That’s not done with
psql
, but instead it’s done with createdb
(a separate external command; see the PostgreSQL createdb documentation) at the operating system command line:On success, there is no visual feedback. Thanks, PostgreSQL.
Adding tables and records
Creating a table (CREATE TABLE)
To add a table schema to the database:
And
psql
responds with:For more see
CREATE TABLE
in the PostgreSQL official docs.Adding a record (INSERT INTO)
- Here’s how to add a record, populating every field:
PostgreSQL responds with:
- Try it again and you get a simliar response.
Adding (inserting) several records at once
- You can enter a list of records using this syntax:
Adding only specific (columns) fields from a record
You can add records but specify only selected fields (also known as columns). MySQL will use common sense default values for the rest.
In this example, only the
name
field will be populated. The sku
column is left blank, and the id
column is incremented and inserted.Two records are added:
PostgreSQL responds with the number of records inserted:
For more on INSERT, see
INSERT
in the PostgreSQL official docsDoing a simple query–get a list of records (SELECT)
Probably the most common thing you’ll do with a table is to obtain information about itwith the
SELECT
statement. It’s a huge topic- Let’s list all the records in the
product
table:
The response:
Postgresql Online Practice
Note
If your table has mixed case objects such as column names or indexes, you’ll need to enclose them in double quotes. For example, If a column name were
Product
instead of product
your query would need to look like this:For more on SELECT, see the
SELECT
in the PostgreSQL official docs.Maintenance and operations issues
Locate the pg_hba.conf file
Postgres configuration is stored in a file named
pg_hba.conf
somewhere in the file system, butthat location varies widely. The way to find it is to use show hba_file
like this:See below for hot reloading this file while Postgres is running.
Reload the configuration file while Postgres is running
If you make changes to the
pg_hba.conf
Postgres configuration sometimes you need to restart.But you may just choose to reload the pg_hba.conf
configuration file like this:Reference
- PostgreSQL offical docs: Server Administration
psql
, a.k.a the PostgreSQL interactive terminalcreatedb
in the PostgreSQL offical docsCREATE TABLE
in the PostgreSQL official docsINSERT
in the PostgreSQL official docs
2020-10-15 - pgAdmin 4 v4.27 Released
The pgAdmin Development Team are pleased to announce pgAdmin 4 version 4.27. This release of pgAdmin 4 includes 28 bug fixes and new features. For more details please see the release notes.
Notable changes in this release include:
Postgresql Online Tester
- Added Macro support.
- Added support to view trigger function under the respective trigger node.
- Allow user to change the database connection from an open query tool tab.
- Added support to ignore the owner while comparing objects in the Schema Diff tool.
- Merged the latest code of 'pgcli' used for the autocomplete feature.
- Fixed invalid literal issue when fetching dependencies for Materialized View.
- Fixed an issue where schema diff is showing identical table as different due to default vacuum settings.
- Ensure that the user should be able to change the start value of the existing sequence.
- Fixed an issue where the query tool is not fetching more than 1000 rows for the table does not have any primary key.
- Fixed an issue where 'Rows X' column values were not visible properly for Explain Analyze in Dark theme.
- Fixed an issue where file extension is stripped on renaming a file.
Download your copy now!
2020-09-17 - pgAdmin 4 v4.26 Released
The pgAdmin Development Team are pleased to announce pgAdmin 4 version 4.26. This release of pgAdmin 4 includes 30 bug fixes and new features. For more details please see the release notes.
Notable changes in this release include:
- Added SQL Formatter support in Query Tool.
- Added a new button to the query tool toolbar to open a new query tool window.
- Added shared server support for admin users.
- Warn the user when connecting to a server that is older than pgAdmin supports.
- Ensure that schema names starting with 'pg' should be visible in browser tree when standard_conforming_strings is set to off.
- Fixed an issue where --load-server does not allow loading connections that use pg_services.
- Fixed string indices must be integers issue for PostgreSQL < 9.3.
- Fixed an issue where the application ignores the fixed port configuration value.
- Remove illegal argument from trigger function in trigger DDL statement.
- Ensure that 'setup-web.sh' should work in Debian 10.
- Fixed excessive CPU usage by stopping the indefinite growth of the graph dataset.
Download your copy now!
2020-08-20 - pgAdmin 4 v4.25 Released
The pgAdmin Development Team are pleased to announce pgAdmin 4 version 4.25. This release of pgAdmin 4 includes 30 bug fixes and new features. For more details please see the release notes.
Notable changes in this release include:
- Modified schema diff tool to compare two databases instead of two schemas
- Resolve schema diff dependencies by selecting the appropriate node automatically and maintain the order in the generated script.
- Replace charting library Flotr2 with ChartJS using React.
- Upgrade font-awesome from v4 to v5.
- Fixed an issue where debugger doesn't work if the search path is set other than 'public'.
- Fixed ssh tunnel hang issue when the user tries to disconnect the server.
- Fixed an issue where conversion of bytea to the binary string results in an error.
- Fixed an issue where the entire logs are in red text when the user runs backup and restore.
- Ensure that the user will be able to modify the start value of the Identity column.
- Fixed an issue where 'ALTER VIEW' statement is missing when the user sets the default value of a column for View.
Download your copy now!
2020-07-23 - pgAdmin 4 v4.24 Released
The pgAdmin Development Team are pleased to announce pgAdmin 4 version 4.24. This release of pgAdmin 4 includes 34 bug fixes and new features. For more details please see the release notes.
Notable changes in this release include:
- Support configuration files that are external to the application installation.
- Added support for LDAP authentication with different DN by setting the dedicated user for the LDAP connection.
- Added support for schema level restriction.
- Added RLS Policy support in Schema Diff.
- Added support for permissive/restricted policy type while creating RLS Policy.
- Added support for LDAP anonymous binding.
- Added High Contrast theme support.
- Added missing dependencies/dependent and corrected some wrongly identified.
- Replace the runtime themes with ones that don't have sizing issues.
- Fixed tab indent issue on a selection of lines is deleting the content when 'use spaces true' in the preferences.
- Fixed CSRF errors when pgAdmin opened in an iframe on safari browser.
Download your copy now!
Postgresql Online Ide
2020-06-25 - pgAdmin 4 v4.23 Released
The pgAdmin Development Team are pleased to announce pgAdmin 4 version 4.23. This release of pgAdmin 4 includes 19 bug fixes and new features. For more details please see the release notes.
Note: We are pleased to announce a number of new packaging options for pgAdmin with this release. Note that as these packages are all new, they have only been tested by the pgAdmin development team and its possible issues may be found in general use. We will aim to resolve any issues reported as quickly as possible. Please report any issues , making sure you include any error messages and details of the platform you're running on.
Windows 64 bit
Postgresql Org Download
Windows users can now choose to use a new 64-bit build of pgAdmin. This is being published alongside the 32-bit build which will be discontinued in a future release. If you already have the 32-bit build of pgAdmin installed on Windows, you must uninstall it before installing the 64-bit build.
Linux Packages
We now have pre-built native packages for popular RPM and DEB based platforms. These are all built in a consistent way and are designed to avoid the dependency issues are seen with other Linux packages in the past.
RHEL/CentOS/Fedora
Debian/Ubuntu
PyPi
Following the last release of pgAdmin, v4.22 was published to the Python package index (PyPi). This will continue with future releases, enabling users of Python 3.4 and later to install quickly and easily. Please see the Python download page for more information:
Notable changes in this release include:
- Added option to ignore the whitespaces while comparing objects in schema diff.
- Added server group name while selecting servers in schema diff.
- Added support of Row Security Policies.
- Improve error messaging if the storage and log directories cannot be created.
- Cleanup Windows build scripts and ensure Windows x64 builds will work.
- Fixed an issue where the Edge browser version is showing wrong and warning message gets displayed.
- Fixed an issue where select all checkbox only selects the first 50 tables.
- Fixed an issue where two identical tables showing different by schema diff tool.
- Fixed an issue when dumping servers from a desktop pgAdmin app by providing an option '--sqlite-path'
- Ensure that the query tool panel gets closed when clicking on the 'Don't Save' button.
Download your copy now!
2019-11-21 - Try pgAdmin online!
Our friends at EnterpriseDB have kindly made an online demo environment for pgAdmin available to allow new users to try it out in their browser without needing to download or install any software. The environment (based on the Katacoda learning platform) includes pgAdmin and PostgreSQL 12, preloaded with the pagila sample database, and is unique to every user allowing a far better experience than typical shared demo environments.
Compile Postgresql Online
Try it out now!
2018-07-12 - pgAgent v4.0.0 Released
The pgAdmin Development Team are pleased to announce the release of pgAgent v4.0.0.
pgAgent is a job scheduler for PostgreSQL; for more information please see the documentation included as part of the pgAdmin documentation at https://www.pgadmin.org/docs/pgadmin4/3.x/pgagent.html.
Download (source): https://www.pgadmin.org/download/pgagent-source-code/
We expect DEB and RPM packages to be available from the PostgreSQL APT/YUM repositories in due course, as well as an updated installer from EnterpriseDB available through StackBuilder.
Notable changes in this release include:
- Remove the dependency on wxWidgets. pgAgent now uses Boost for thread management and synchronisation [Neel Patel]
- Refactor connection parsing logic to fix issues with and improve handling of connection strings [Thomas Krennwallner]
- Handle 2 digit server version numbers [Ashesh Vashi]
- Fix handling of the 'succeeded' flag on job steps which could prevent failure of steps causing the following steps to fail [Sanket Mehta]