|
Learning SQL
SQL (Structured Query Language) is a standard programming
language for generating, manipulating, and retrieving
information from a relational database. If you're working
with a relational database--whether you're writing
applications, performing administrative tasks, or generating
reports--you need to know how to interact
with your data.
Even if you are using a tool that generates SQL for you,
such as a reporting tool, there may still be cases where you
need to bypass the automatic generation feature and write
your own SQL statements.
To help you attain this fundamental SQL knowledge, look to
Learning SQL, an introductory guide to SQL, designed
primarily for developers just cutting their teeth on the
language.
Learning SQL moves you quickly through the basics and then
on to some of the more commonly used advanced features.
Among the topics discussed:
The history of the computerized database
SQL Data Statements--those used to create, manipulate, and
retrieve data stored in your database; example statements
include select, update, insert, and delete
SQL Schema Statements--those used to create database
objects, such as tables, indexes, and constraints
How data sets can interact with queries
The importance of subqueries
Data conversion and manipulation via SQL's built-in
functions
How conditional logic can be used in Data Statements
Best of all, Learning SQL talks to you in a real-world
manner, discussing various platform differences that you're
likely to encounter and offering a series of chapter
exercises that walk you through the learning process.
Whenever possible, the book sticks to the features included
in the ANSI SQL standards. This means you'll be able to
apply what you learn to any of several different databases;
the book covers MySQL, Microsoft SQL Server, and Oracle
Database, but the features and syntax should apply just as
well (perhaps with some tweaking) to IBM DB2, Sybase
Adaptive Server, and PostgreSQL.
Put the power and flexibility of SQL to work. With Learning
SQL you can master this important skill and know that the
SQL statements you write are indeed correct.
Preface
1. A Little Background
Introduction to Databases
What Is SQL?
What Is MySQL?
What's in Store
2. Creating and Populating a Database
Creating a MySQL Database
Using the mysql Command-Line Tool
MySQL Data Types
Table Creation
Populating and Modifying Tables
When Good Statements Go Bad
The Bank Schema
3. Query Primer
Query Mechanics
Query Clauses
The select Clause
The from Clause
The where Clause
The group by and having Clauses
The order by Clause
Exercises
4. Filtering
Condition Evaluation
Building a Condition
Condition Types
NULL: That Four-Letter Word
Exercises
5. Querying Multiple Tables
What Is a Join?
Joining Three or More Tables
Self-Joins
Equi-Joins Versus Non-Equi-Joins
Join Conditions Versus Filter Conditions
Exercises
6. Working with Sets
Set Theory Primer
Set Theory in Practice
Set Operators
Set Operation Rules
Exercises
7. Data Generation, Conversion, and Manipulation
Working with String Data
Working with Numeric Data
Working with Temporal Data
Conversion Functions
Exercises
8. Grouping and Aggregates
Grouping Concepts
Aggregate Functions
Generating Groups
Group Filter Conditions
Exercises
9. Subqueries
What Is a Subquery?
Subquery Types
Noncorrelated Subqueries
Correlated Subqueries
When to Use Subqueries
Subquery Wrap-up
Exercises
10. Joins Revisited
Outer Joins
Cross Joins
Natural Joins
Exercises
11. Conditional Logic
What Is Conditional Logic?
The Case Expression
Case Expression Examples
Exercises
12. Transactions
Multiuser Databases
What Is a Transaction?
13. Indexes and Constraints
Indexes
Constraints
A. ER Diagram for Example Database
B. MySQL Extensions to the SQL Language
C. Solutions to Exercises
D. Further Resources
Index
|
