-->

• Postgresql Identity
• Postgresql Identity Insert
• Postgresql Ident
• Postgresql Identified By

Express is a free edition that provides basic functionality of an integrated development environment for PostgreSQL database management, administration, and development. Standard edition. Comes with a full package of advanced features and built-in tools that substantially extend the Express edition's functionality. 除了作为PostgreSQL的GUI工具，DataGrip还能为版本控制系统之类服务提供全方位的IDE。 缺点： 由于不是PostgreSQL的原生工具，因此它不太方便调试各种错误，也无法显示所有的错误。 其学习曲线较为“陡峭”，对于初学者的门槛较高。 比较消耗RAM的系统资源。. PostgreSQL - The official PostgreSQL website provides instructions on how to download and setup their driver: psqlODBC - PostgreSQL ODBC driver RStudio Professional Drivers - RStudio Server Pro, RStudio Connect, or Shiny Server Pro users can download and use RStudio Professional Drivers at no additional charge.

In this tutorial, you use Azure CLI (command-line interface) and other utilities to learn how to:

• Create an Azure Database for PostgreSQL server
• Configure the server firewall
• Use psql utility to create a database
• Load sample data
• Query data
• Update data
• Restore data

You may use the Azure Cloud Shell in the browser, or install Azure CLI on your own computer to run the commands in this tutorial.

Use Azure Cloud Shell

Azure hosts Azure Cloud Shell, an interactive shell environment that you can use through your browser. You can use either Bash or PowerShell with Cloud Shell to work with Azure services. You can use the Cloud Shell preinstalled commands to run the code in this article without having to install anything on your local environment.

To start Azure Cloud Shell:

Option	Example/Link
Select Try It in the upper-right corner of a code block. Selecting Try It doesn't automatically copy the code to Cloud Shell.
Go to https://shell.azure.com, or select the Launch Cloud Shell button to open Cloud Shell in your browser.
Select the Cloud Shell button on the menu bar at the upper right in the Azure portal.

To run the code in this article in Azure Cloud Shell:

1. Start Cloud Shell.

2. Select the Copy button on a code block to copy the code.

3. Paste the code into the Cloud Shell session by selecting Ctrl+Shift+V on Windows and Linux or by selecting Cmd+Shift+V on macOS.

4. Select Enter to run the code.

If you choose to install and use the CLI locally, this article requires that you are running the Azure CLI version 2.0 or later. Run az --version to find the version. If you need to install or upgrade, see Install Azure CLI.

If you have multiple subscriptions, choose the appropriate subscription in which the resource exists or is billed for. Select a specific subscription ID under your account using az account set command.

Create a resource group

Create an Azure resource group using the az group create command. A resource group is a logical container into which Azure resources are deployed and managed as a group. The following example creates a resource group named myresourcegroup in the westus location.

Create an Azure Database for PostgreSQL server

Create an Azure Database for PostgreSQL server using the az postgres server create command. A server contains a group of databases managed as a group.

The following example creates a server called mydemoserver in your resource group myresourcegroup with server admin login myadmin. The name of a server maps to DNS name and is thus required to be globally unique in Azure. Substitute the <server_admin_password> with your own value. It is a General Purpose, Gen 5 server with 2 vCores.

The sku-name parameter value follows the convention {pricing tier}_{compute generation}_{vCores} as in the examples below:

• --sku-name B_Gen5_2 maps to Basic, Gen 5, and 2 vCores.
• --sku-name GP_Gen5_32 maps to General Purpose, Gen 5, and 32 vCores.
• --sku-name MO_Gen5_2 maps to Memory Optimized, Gen 5, and 2 vCores.

Please see the pricing tiers documentation to understand the valid values per region and per tier.

Important

The server admin login and password that you specify here are required to log in to the server and its databases later in this quickstart. Remember or record this information for later use.

By default, postgres database gets created under your server. The postgres database is a default database meant for use by users, utilities, and third-party applications.

Configure a server-level firewall rule

Create an Azure PostgreSQL server-level firewall rule with the az postgres server firewall-rule create command. A server-level firewall rule allows an external application, such as psql or PgAdmin to connect to your server through the Azure PostgreSQL service firewall.

You can set a firewall rule that covers an IP range to be able to connect from your network. The following example uses az postgres server firewall-rule create to create a firewall rule AllowMyIP that allows connection from a single IP address.

To restrict access to your Azure PostgreSQL server to only your network, you can set the firewall rule to only cover your corporate network IP address range.

Note

Azure PostgreSQL server communicates over port 5432. When connecting from within a corporate network, outbound traffic over port 5432 may not be allowed by your network's firewall. Have your IT department open port 5432 to connect to your Azure SQL Database server.

Get the connection information

To connect to your server, you need to provide host information and access credentials.

The result is in JSON format. Make a note of the administratorLogin and fullyQualifiedDomainName.

Connect to Azure Database for PostgreSQL database using psql

If your client computer has PostgreSQL installed, you can use a local instance of psql, or the Azure Cloud Console to connect to an Azure PostgreSQL server. Let's now use the psql command-line utility to connect to the Azure Database for PostgreSQL server.

1. Run the following psql command to connect to an Azure Database for PostgreSQL database:

   For example, the following command connects to the default database called postgres on your PostgreSQL server mydemoserver.postgres.database.azure.com using access credentials. Enter the <server_admin_password> you chose when prompted for password.

   Tip

   If you prefer to use a URL path to connect to Postgres, URL encode the @ sign in the username with %40. For example the connection string for psql would be,

2. Once you are connected to the server, create a blank database at the prompt:

3. At the prompt, execute the following command to switch connection to the newly created database mypgsqldb:

Create tables in the database

Now that you know how to connect to the Azure Database for PostgreSQL, you can complete some basic tasks:

First, create a table and load it with some data. For example, create a table that tracks inventory information:

You can see the newly created table in the list of tables now by typing:

Load data into the table

Now that there is a table created, insert some data into it. At the open command prompt window, run the following query to insert some rows of data:

You have now added two rows of sample data into the table you created earlier.

Query and update the data in the tables

Execute the following query to retrieve information from the inventory table:

You can also update the data in the inventory table:

You can see the updated values when you retrieve the data:

Restore a database to a previous point in time

Imagine you have accidentally deleted a table. This is something you cannot easily recover from. Azure Database for PostgreSQL allows you to go back to any point-in-time for which your server has backups (determined by the backup retention period you configured) and restore this point-in-time to a new server. You can use this new server to recover your deleted data.

The following command restores the sample server to a point before the table was added:

The az postgres server restore command needs the following parameters:

Setting	Suggested value	Description
resource-group	myresourcegroup	The resource group in which the source server exists.
name	mydemoserver-restored	The name of the new server that is created by the restore command.
restore-point-in-time	2017-04-13T13:59:00Z	Select a point-in-time to restore to. This date and time must be within the source server's backup retention period. Use ISO8601 date and time format. For example, you may use your own local timezone, such as 2017-04-13T05:59:00-08:00, or use UTC Zulu format 2017-04-13T13:59:00Z.
source-server	mydemoserver	The name or ID of the source server to restore from.

Restoring a server to a point-in-time creates a new server, copied as the original server as of the point in time you specify. The location and pricing tier values for the restored server are the same as the source server.

The command is synchronous, and will return after the server is restored. Once the restore finishes, locate the new server that was created. Verify the data was restored as expected.

Next steps

In this tutorial, you learned how to use Azure CLI (command-line interface) and other utilities to:

• Create an Azure Database for PostgreSQL server
• Configure the server firewall
• Use psql utility to create a database
• Load sample data
• Query data
• Update data
• Restore data

Next, learn how to use the Azure portal to do similar tasks, review this tutorial: Design your first Azure Database for PostgreSQL using the Azure portal

• PostgreSQL Tutorial

• Advanced PostgreSQL

• PostgreSQL Interfaces

Postgresql Identity

• PostgreSQL Useful Resources

• Selected Reading

Postgresql Identity Insert

PostgreSQL has the data types smallserial, serial and bigserial; these are not true types, but merely a notational convenience for creating unique identifier columns. These are similar to AUTO_INCREMENT property supported by some other databases.

If you wish a serial column to have a unique constraint or be a primary key, it must now be specified, just like any other data type.

The type name serial creates an integer columns. The type name bigserial creates a bigint column. bigserial should be used if you anticipate the use of more than 2³¹ identifiers over the lifetime of the table. The type name smallserial creates a smallint column.

Postgresql Ident

Syntax

The basic usage of SERIAL dataype is as follows −

Example

Postgresql Identified By

Consider the COMPANY table to be created as follows −

Now, insert the following records into table COMPANY −

This will insert seven tuples into the table COMPANY and COMPANY will have the following records −