Book Image

Learn SQL Database Programming

By : Josephine Bush
5 (1)
Book Image

Learn SQL Database Programming

5 (1)
By: Josephine Bush

Overview of this book

SQL is a powerful querying language that's used to store, manipulate, and retrieve data, and it is one of the most popular languages used by developers to query and analyze data efficiently. If you're looking for a comprehensive introduction to SQL, Learn SQL Database Programming will help you to get up to speed with using SQL to streamline your work in no time. Starting with an overview of relational database management systems, this book will show you how to set up and use MySQL Workbench and design a database using practical examples. You'll also discover how to query and manipulate data with SQL programming using MySQL Workbench. As you advance, you’ll create a database, query single and multiple tables, and modify data using SQL querying. This SQL book covers advanced SQL techniques, including aggregate functions, flow control statements, error handling, and subqueries, and helps you process your data to present your findings. Finally, you’ll implement best practices for writing SQL and designing indexes and tables. By the end of this SQL programming book, you’ll have gained the confidence to use SQL queries to retrieve and manipulate data.
Table of Contents (24 chapters)
Section 1: Database Fundamentals
Section 2: Basic SQL Querying
Section 3: Advanced SQL Querying
Section 4: Presenting Your Findings
Section 5: SQL Best Practices

Using the GROUP BY clause

The GROUP BY clause allows you to group rows that have the same values into summary rows. This clause is often used with aggregate functions, which were covered in the previous section of this chapter. It's an optional clause that can be used on a SELECT statement.

The following code shows the GROUP BY syntax, where the WHERE and ORDER BY clauses are optional:

SELECT column(s) 
FROM table
WHERE condition(s)
GROUP BY columns(s)
ORDER BY column(s);

Understanding how GROUP BY works without aggregate functions

Let's say you want to find the distinct list of player ID's and the teams they've played for. You can execute a query like the following:

USE lahmansbaseballdb;
SELECT playerid...