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

Processing your dataset

After you've gotten to know your data, you may need to fix issues residing in it. This section will do a walkthrough of some methods you can use to address the problems you may encounter in your dataset.

Fixing rare and outlier values

Detecting rare and outlier values can help you determine if you have bad or irrelevant data. To proceed from where we left off in the detecting rare and outlier values section, execute the following query:

USE lahmansbaseballdb; 
SELECT DISTINCT h as hits, COUNT(h) as count
FROM batting
ORDER BY count;

The preceding query will give you a list of each distinct value in the h (hits) column and a count of those hits, as shown in the following two screenshots...