Book Image

Learn PostgreSQL

By : Luca Ferrari, Enrico Pirozzi
Book Image

Learn PostgreSQL

By: Luca Ferrari, Enrico Pirozzi

Overview of this book

PostgreSQL is one of the fastest-growing open source object-relational database management systems (DBMS) in the world. As well as being easy to use, it’s scalable and highly efficient. In this book, you’ll explore PostgreSQL 12 and 13 and learn how to build database solutions using it. Complete with hands-on tutorials, this guide will teach you how to achieve the right database design required for a reliable environment. You'll learn how to install and configure a PostgreSQL server and even manage users and connections. The book then progresses to key concepts of relational databases, before taking you through the Data Definition Language (DDL) and commonly used DDL commands. To build on your skills, you’ll understand how to interact with the live cluster, create database objects, and use tools to connect to the live cluster. You’ll then get to grips with creating tables, building indexes, and designing your database schema. Later, you'll explore the Data Manipulation Language (DML) and server-side programming capabilities of PostgreSQL using PL/pgSQL, before learning how to monitor, test, and troubleshoot your database application to ensure high-performance and reliability. By the end of this book, you'll be well-versed with the Postgres database and be able to set up your own PostgreSQL instance and use it to build robust solutions.
Table of Contents (27 chapters)
Section 1: Getting Started
Section 2: Interacting with the Database
Section 3: Administering the Cluster
Section 4: Replication
Section 5: The PostegreSQL Ecosystem

Understanding basic table manipulation statements

Now that you have learned how to create tables, you need to understand how to insert, view, modify, and delete data in the tables. This will help you update any incorrect entries, or update existing entries, as needed. There are a variety of commands that can be used for this, which we will look at now.

Inserting and selecting data

In this section, we will learn how to insert data into tables. To insert data into tables, you need to use the INSERT command. The INSERT command inserts new rows into a table. It is possible to insert one or more rows specified by value expressions, or zero or more rows resulting from a query. We will now go through some use cases as follows:

  1. To insert a new user in the users table, execute the following command:
forumdb=# insert into users (username,gecos,email) values ('myusername','mygecos','myemail');

This result shows that PostgreSQL has inserted one record into...