1. Introduction

Welcome to the DBMaker Database Administrator's Reference. DBMaker is a powerful and flexible SQL Database Management System (DBMS) that supports an interactive Structured Query Language (SQL), a Microsoft Open Database Connectivity (ODBC) compatible interface, and Embedded SQL for C (ESQL/C). The unique open architecture and native ODBC interface give you the freedom to build custom applications using a wide variety of programming tools, or query your database using existing ODBC-compliant applications.

DBMaker is easily scalable from personal single-user databases to distributed enterprise-wide databases. Regardless of the configuration you choose for your database, the safety of your critical data is ensured by the advanced security, integrity, and reliability features of DBMaker. Extensive cross-platform support permits you to leverage your existing hardware now, and allows you to expand and upgrade to more powerful hardware as your needs grow.

DBMaker provides excellent multimedia handling capabilities, allowing you to store, search, retrieve, and manipulate all types of multimedia data. Binary Large Objects (BLOBs) allow you to ensure the integrity of your multimedia data by taking full advantage of the advanced security and crash recovery mechanisms included in DBMaker. File Objects (FOs) allow you to manage your multimedia data while maintaining the capability to edit individual files in the source application.

1.1 Who Should Read this Book?

This book is intended for end users who are not familiar with either relational databases or the SQL language. However, you should have a general working knowledge of computers, and should be comfortable using the operating system you are using to run DBMaker. Information on the operating system is beyond the scope of this book, and you should consult your operating system documentation if you encounter any problems in this area.

1.2 Information in this Book

This book contains general information on the concepts and principles needed to understand the organization and structure of a database that is created and maintained using DBMaker. This information is presented in manageable segments on a single topic. To help you understand the information presented more clearly, examples and illustrations are provided where possible.

Since this book is only intended as an introduction to DBMaker (and relational databases in general), not all relational database concepts may be covered fully. However, all concepts that are presented will be covered with enough depth to let you understand what you are doing in the tutorial examples, and why.

The SQL language as implemented by DBMaker is fully covered in this book, and syntax diagrams for all commands are provided where the command first appears. The syntax diagrams allow you to see at a glance all the possible options and syntax variations for each command. Explanations of all SQL commands are always supplemented with several examples and notes on important points to watch for when using the command.

Most of the concepts, commands, and examples in this book are presented using dmSQL, the command-line tool provided with DBMaker. In a few cases operations can only be performed using one of the other DBMaker application tools or utilities. For more detailed information on how to use the application tools and utilities provided with DBMaker, please refer to "Other Sources of Information" later in this chapter.

1.3 Other Sources of Information

DBMaker provides many other user's guides and reference manuals in addition to this tutorial. For more detailed information on a particular subject, you should consult one of the books shown below.

For more information on the tools and utilities provided with DBMaker, refer to the dmSQL User's Guide, the DBATool User's Guide, or the Server Manager User's Guide.
For more information on the SQL language implemented by DBMaker, refer to the SQL Command and Function Reference.
For more information on error and warning messages, refer to the Error and Message Reference.

The subjects listed above are the subjects that you may find most useful when working through the tutorial. Not all of the DBMaker manuals are listed simply because subjects covered by some manuals may be more relevant to database administrator's or application developers. For information on subjects not listed above, refer to the complete set of manuals provided with DBMaker.

1.4 Document Conventions

This book uses a standard set of typographic conventions to make reading easier and clearer.

Italics

Italics indicate placeholders for information you must supply, such as user names and table names. The word in italics should not be typed, but should be replaced by the actual name you want to use. Italics also introduce new words, and are occasionally used for emphasis in text.

Boldface

Boldface indicates filenames, database names, table names, column names, and other similar terms.

Computer

Information that is displayed on the screen is presented in this type. This includes lines that the product displays in response to your input, as well as lines you are required to enter.

KEYWORDS

All keywords used by the SQL language appear in uppercase when used in text.

small caps

Small capital letters indicate keys on the keyboard. A plus sign (+) between two key names indicates you should hold down the first key while pressing the second. A comma (,) between two key names indicates you should release the first key before pressing the second key.

1.5 How to Use This Book

If you are not familiar with relational database concepts and principles, or have never used the SQL language, you should read this book before any of the other manuals provided with DBMaker.

This book is designed to be read from start to finish, and all of the examples in this book are based on the tutorial database that is created as you work through the examples in each chapter. It is recommended that you do each of the examples in the order they appear, since skipping any of them may mean some important data that may be used by later examples is not available. In some cases, skipping examples may produce unexpected results or errors in subsequent examples.

If you are already familiar with databases and only want to try some of the features found in specific chapters, this is also possible. However, you must first set up the tutorial database for use with that chapter, so that all data required to perform the examples in that chapter is available. To do this, you must run one of the script files provided together with this manual. For more information on the tutorial database and how to use the script files, please refer to The Tutorial Database later in this chapter. Note that after you run the appropriate script files, you must still perform all of the steps in that chapter in the order they appear to get the correct results and avoid any errors.

1.6 Syntax Diagrams

Syntax diagrams show the syntax for all SQL commands. These diagrams provide assistance when you are constructing a statement on the command line, but cannot remember the syntax and all possible options. An example syntax diagram is shown below.

To use the syntax diagram, simply follow the line from start to finish. Any elements of the command that you cannot navigate around are required. Any elements that you can navigate around are optional, but provide additional options or flexibility.

Figure 1-1: Sample syntax diagram

Any words that appear in italics are placeholders for the actual names used in your database. You should substitute the actual names for these placeholders. In the above diagram, you should replace the table_name placeholder with the name of a table in the database. For example, in the tutorial database, you could replace the table_name placeholder with Customers to execute this command on the Customers table.

You should also note the direction of the arrows. Sometimes it is possible to have a list of items in a command, which is shown in the syntax diagram as a circular path. Both column name fields above can include a list of column names, separated by commas, as is indicated by the circular path you can take by following the arrows.