01-HoffmanSQL - Introduction to Structured Query Language - Version 4.66

Oct 25, 2026

An introductory tutorial to Structured Query Language (SQL), presenting standard ANSI SQL concepts and delaying vendor-specific features until the Nonstandard SQL section. The material explains how relational data is stored in tables and how to query it using SELECT, including selecting specific columns, all rows, and using WHERE for conditional filtering with relational operators. It includes worked examples with example table schemas and results, plus a structured outline of further topics such as joins, keys, aggregates, views, and subqueries.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages34

Reading Time1 h 26 min

AccessFree to download

Introduction to Structured Query Language

Basics of the SELECT Statement

Conditional Selection

Relational Operators

Compound Conditions

IN & BETWEEN

Using LIKE

Joins

Keys

Performing a Join

Eliminating Duplicates

Aliases & In/Subqueries

Aggregate Functions

Views

Creating New Tables

Altering Tables

Adding Data

Deleting Data

Updating Data

Indexes

GROUP BY & HAVING

More Subqueries

EXISTS & ALL

UNION & Outer Joins

Embedded SQL

Common SQL Questions

Nonstandard SQL

Syntax Summary

Exercises

Important Links

Hoffman, James. 2001. Introduction to Structured Query Language. Version 4.66. [http://www.highcroft.com/highcroft/sql_intro.pdf](http://www.highcroft.com/highcroft/sql_intro.pdf) Introduction to Structured Query Language Version 4.66 Copyright 1996-2001, James Hoffman [j](jhoffman@one.net)[hoffman@one.net](jhoffman@one.net) Introduction to Structured Query Language Version 4.66 This page is a introductory tutorial of the Structured Query Language (also known as SQL) and is a pioneering effort on the World Wide Web, as this is the first comprehensive SQL tutorial available on the Internet. SQL allows users to access data in relational database management systems, such as Oracle, Sybase, Informix, Microsoft SQL Server, Access, and others, by allowing users to describe the data the user wishes to see. SQL also allows users to define the data in a database, and manipulate that data. This page will describe how to use SQL, and give examples. The SQL used in this document is "ANSI", or standard SQL, and no SQL features of specific database management systems will be discussed until the "Nonstandard SQL" section. It is recommended that you print this page, so that you can easily refer back to previous examples. Also, you may be interested in joining the new SQL Club on Yahoo! , where you can read or enter messages ina SQL forum. Table of Contents Basics ofthe SELECT Statement Conditional Selection Relational Operators Compound Conditions IN & BETWEEN Using LIKE Joins Keys Performing a Join Eliminating Duplicates Aliases & In/Subqueries Aggregate Functions Views Creating New Tables Altering Tables Adding Data Deleting Data Updating Data Indexes GROUP BY & HAVING More Subqueries EXISTS & ALL UNION & Outer Joins Embedded SQL [http://w3.one.net/](http://w3.one.net/)~jhoffman/sqltut.htm Page 1 SQL Tutorial 04/07/2001 Common SQL Questions Nonstandard SQL Syntax Summary Exercises Important Links Basics ofthe SELECT Statement In a relational database, data is stored in tables. An example table would relate Social Security Number, Name, and Address: | EmployeeAddressTable | | | | | | | --- | --- | --- | --- | --- | --- | | SSN | FirstName | LastName | Address | City | State | | 512687458 | Joe | Smith | 83 First Street | Howard | Ohio | | 758420012 | Mary | Scott | 842 Vine Ave. | Losantiville | Ohio | | 102254896 | Sam | Jones | 33 Elm St. | Paris | New York | | 876512563 | Sarah | Ackerman | 440 U. S. 110 | Upton | Michigan | Now, let's say you want to see the address of each employee. Use the SELECT statement, like so: SELECT FirstName, LastName, Address, City, State FROM EmployeeAddressTable; The following is the results of your query of the database: | First Name | Last Name | Address | City | State | | --- | --- | --- | --- | --- | | Joe | Smith | 83 First Street | Howard | Ohio | | Mary | Scott | 842 Vine Ave. | Losantiville | Ohio | | Sam | Jones | 33 Elm St. | Paris | New York | | Sarah | Ackerman | 440 U. S. 110 | Upton | Michigan | To explain what you just did, you asked for the all of data in the EmployeeAddressTable, and specifically, you asked for the columns called FirstName, LastName, Address, City, and State. Note that column names and table names do not have spaces...they must be typed as one word; and that the statement ends with a semicolon (;). The general form for a SELECT statement, retrieving all of the rows in the table is: SELECT ColumnName, ColumnName, ... FROM TableName; To get all columns ofa table without typing all column names, use: SELECT * FROM TableName; Each database management system (DBMS) and database software has different methods for logging in to the [http://w3.one.net/](http://w3.one.net/)~jhoffman/sqltut.htm Page 2 SQL Tutorial 04/07/2001 database and entering SQL commands; see the local computer "guru" to help you get onto the system, so that you can use SQL. Conditional Selecti

FAQs

What is SQL in this tutorial, and why is it used?

SQL is the Structured Query Language used to access and manipulate data in relational database management systems. It lets users describe the data they want to see and define or change data in a database.

How does the tutorial use the SELECT statement to retrieve data?

It shows SELECT for returning specific columns from a table (e.g., selecting FirstName, LastName, Address, City, State). It also demonstrates SELECT * FROM TableName to retrieve all columns.

How does WHERE work with relational operators in SQL examples here?

The tutorial explains that WHERE filters rows based on conditions evaluated as true or false. It gives examples using operators like >= for numeric criteria and = with quoted strings (e.g., POSITION = 'Manager').

Oct 25, 2026

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