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Databases: Most Popular Articles

These articles are the most popular over the last month.
SQL Server Stored Procedures
Microsoft SQL Server provides the stored procedure mechanism to simplify the database development process by grouping Transact-SQL statements into manageable blocks.
Database Normalization Basics
Database normalization can save storage space and ensure the consistency of your data. Learn the basics in this introductory article.
Microsoft Access Fundamentals
Want to learn how to use Microsoft Access? Find out on the About.com Databases site!
Creating Forms in Access
Learn how to create a simple form in Microsoft Access. This tutorial walks you through the process step-by-step!
Introduction to SQL
Would you like to learn SQL? This tutorial will introduce you to the basics.
First Normal Form
In this article, we begin our look at the first of three major normal forms -- first normal form (otherwise known as 1NF).
Creating a Simple Query in Microsoft Access
Want to learn how to create a query in Microsoft Access? Find out on the About.com Databases site!
Building an Access Database...
In this series of Microsoft Access tutorials, we follow the database administrators for Patrick's Widgets as they build a Microsoft Access database from the ground up.
Entity-Relationship Diagram
What is a database? Find out here!
Database Software Options
You've finally buckled down and decided that it's time to purchase a database solution for your home or business. What type of database do you need? It's actually a simple matter of deciding what features you need and choosing a product that meets your requirements and doesn't cause too much pain in your pocketbook.
Primary Key
What is a primary key? Find out here!
Microsoft Access Reports Tutorial
Would you like to create professional-looking reports from your Microsoft Access database with the click of a mouse? Follow along as we walk through the simple process of designing a reusable report.
Converting Excel to Access
Are you ready to convert your unwieldy Excel spreadsheet to a flexible Access database? Let us walk you through the process!
Databases for Beginners
Are you new to the world of databases? Wondering where to get started? In this series of articles, we introduce you to the basics of database technology and help you get started in this exciting field.
What is a Database?
Databases are designed to offer an organized mechanism for storing, managing and retrieving information. They do so through the use of tables. If you’re familiar with spreadsheets like Microsoft Excel, you’re probably already accustomed to storing data in tabular form. It’s not much of a stretch to make the leap from spreadsheets to databases.
Third Normal Form (3NF)
In our first article, we looked at the basic requirements of 3NF. Here they are again to refresh your memory: meet the requirements of 1NF and 2NF and remove columns that are not fully dependent upon the primary key.
Second Normal Form
Second Normal Form allows you to enhance the normalization of your database. In this article, we explore the requirements of 2NF and the process of normalizing your database.
Databases Glossary
Glossary of database related terms from your About.com Guide to Databases
Creating Database Relationships in Access
Join us as we walk through the process of creating database relationships in Microsoft Access.
Dynamic Web Pages With Access
Want to create dynamic, server-generated HTML from your Access database? This step-by-step tutorial will walk you through the process.
Introduction to SQL Server
SQL Server offers full-featured relational database functionality in a user-oriented package. Learn about the various components of SQL Server in this article.
Creating Databases and Tables
Learn to create databases and tables using the Structured Query Language (SQL) in this step-by-step tutorial from your About.com Guide to Databases.
Summarizing Data with CUBE and ROLLUP
SQL's CUBE and ROLLUP commands allow for the efficient summarization of data. Learn how to use them here!
Choosing a Database
Database management systems (or DBMSs) can be divided into two categories -- desktop databases and server databases. Generally speaking, desktop databases are oriented toward single-user applications and reside on standard personal computers (hence the term desktop). Server databases contain mechanisms to ensure the reliability and consistency of data and are geared toward multi-user applications.
Database Keys
As you may already know, databases use tables to organize information. Each table consists of a number of rows, each of which corresponds to a single database record. So, how do databases keep all of these records straight? It’s through the use of keys.
ZIP Code Database
This free Access database of ZIP codes provides database designers with a valuable tool to assist in mapping ZIP codes to a city/state pair and even provides the latitude and longitude of that location.
Retrieving Data from Multiple Tables with SQL Joins
SQL joins allow you to retrieve data from multiple database tables. Your About.com Guide to Databases provides a comprehensive introduction.
Self-Joins in SQL
You can use a self-join to simplify nested SQL queries where the inner and outer queries reference the same table. These joins allow you to retrieve related records from the same table.
Creating Relationships
In the seventh installment of our Building an Access Database From the Ground Up series, we create relationships between our tables to finish implementing our relational model.
Using Self-Joins in SQL
Did you know that you can use a self-join to simplify nested SQL queries where the inner and outer queries reference the same table? Let's take a look at an example.
Aggregate Functions in SQL
Summarize data with SQL's SUM, AVG, MIN, MAX and COUNT functions. Your About.com Guide to Databases walks you through the process.
Structured Query Language
Most large-scale databases use the Structured Query Language (SQL) to define all user and administrator interactions. This language offers a flexible interface for databases of all shapes and sizes.
Foreign Key
What is a foreign key? Find out here!
Data Mining: An Introduction
Data mining allows you to find the needles hidden in your haystacks of data. Learn how to use these advanced techniques to meet your business objectives.
The ACID Model
All database management systems should share four characteristics: Atomicity, Consistency, Isolation and Durability.
SQL Books
Looking for a book to help you get started with Strucutred Query Language? Need a new reference book for your shelf? Check out my favorite SQL books.
Installing Northwind
The Northwind database contains some great sample tables, queries, reports and other database features. Here's how to install it.
SQL Server Replication
Microsoft SQL Server provides a robust replication facility to distribute and update data in a decentralized fashion.
Exporting Access Tables to ...
Microsoft Access allows you to export data to a variety of formats for sharing and analysis. In this tutorial, we walk through the process of exporting an Access table to an Excel workbook.
Referential Integrity
What is Referential Integrity? Find out in our database glossary!
Access File Formats: ACCDB/MDB
The release of Access 2007 brings a new file format. The MDB database files we’ve known for over a decade are now slated to become historical relics. While Access 2007 continues to support MDB databases for backwards compatibility purposes, Microsoft has now introduced the new ACCDB file format as the future standard. Wondering if you should begin using the ACCDB format?
Joining Multiple Tables in SQL
You can use SQL JOIN statements to combine data from three or more tables. In an earlier article, we took a look at using inner joins and outer joins to combine data from two different tables. In many cases, you’ll want to take this a step further and combine data from three or more tables. Let's take a look at the SQL statements that allow you to accomplish this goal for an inner join.
Boyce-Codd Normal Form (BCNF)
What is Boyce-Codd Normal Form (BCNF)? Find out here!
Designing Data Access Pages
Want to design a Data Access Page using Access 2000? This step-by-step tutorial walks you through the process.
Top 5 Desktop Databases
Desktop databases offer simple, flexible solutions for data storage and retrieval. They're often quite sufficient to meet uncomplicated database requirements for both small and large organizations. If you're not sure if a desktop database is right for you, try reading the Choosing a Database series of articles which cover both desktop and server databases in depth
Creating Forms in Access 2007
Although Access provides a convenient spreadsheet-style datasheet view for entering data, it isn’t always an appropriate tool for every data entry situation. If you’re working with users you don’t want to expose to the inner workings of Access, you may choose to use Access forms to create a more user-friendly experience. In this tutorial, we’ll walk through the process of creating an Access form.
Creating Relationships in Access
Join us as we walk through the process of creating database relationships in Microsoft Access.
Sample Excel Document
Sample Excel Document
Candidate Key
What is a Candidate Key? Find out here!
Deleting Data from an SQL Table
The SQL DELETE command allows the removal of some or all of the data stored in a relational database table.
Access 2003 Books
So, you'd like to learn more about Microsoft Access 2003 and you don't know where to begin. I've selected five of my favorite introductory-level Access books for your perusal. Follow the "Compare Prices" links for a competitive listing of prices at various web merchants.
Stored Procedure
Looking for a definition of the database term stored procedure? Find it here in the About Databases glossary.
Third Normal Form (3NF) - Databases Glossary
What is Third Normal Form? Find out here!
Retrieving Data with SQL Queries: Introducing the SELECT Statement
Learn to retrieve information from your database with the SQL SELECT statement. Your About.com Guide to Databases provides a thorough introduction.
SQL Server Administration (70-228) Practice Exam
Looking to prove your SQL Server Administration mettle? This quiz will help you prepare for Microsoft's 70-228 exam: Installing, Configuring, and Administering Microsoft SQL Server 2000 Enterprise Edition. This is a critical step toward earning your Microsoft Certified Database Administrator credential.
Using Expression Builder
Have trouble remembering function names or arguments in Microsoft Access? We all do! Access' Expression Builder is a great tool that walks you through the process of creating expressions for your forms, tables, reports and queries while keeping a handy reference at your fingertips.
Data Input Via Forms
Part VIII of our tutorial introduces you to the concept of Access forms to input and modify data.
Creating Databases and Tables
Learn to create databases and tables using the Structured Query Language (SQL) in this step-by-step tutorial from your About.com Guide to Databases.
Password Protecting Access
Password protecting an Access database allows you to protect your sensitive data from prying eyes. In this tutorial, we walk you through the process of encrypting your database and protecting with a password, step by step.
Access 2007 Relationships
The true power of relational databases lies in their ability to track relationships (hence the name!) between data elements. However, many database users don’t understand how to take advantage of this functionality and simply use Access as an advanced spreadsheet. In this tutorial, we’ll walk through the process of creating a relationship between two tables in an Access database.
SQL Server Disaster Recovery
There are numerous threats to your data -- disk corruption, natural disaster, human error and server failure, among others. Is your disaster recovery plan sufficient to ensure your organization's interests are protected?
Creating the Database File
In part five of our Building An Access Database From the Ground Up series, we create the Access database file that will be used for the Patrick's Widgets database.
Access Controls in SQL
SQL joins allow you to retrieve data from multiple database tables. Your About.com Guide to Databases provides a comprehensive introduction.
Introduction to MySQL
Fed up with the world of commercial software licensing? Are you looking for a stable database platform for your organization but sweating at the hefty price tags attached to mainstream products from Microsoft and Oracle? MySQL may be for you!
Access and the Web
Would you like to share your Access reports with the web? This step-by-step tutorial will walk you through the process.
Access DBs from Templates
Microsoft provides quite a few prebuilt database templates to assist you in jumpstarting your database development process. In this tutorial, we'll walk through the process of creating an Access database using these templates.
SQL Server 2005 Introduction
The long awaited Yukon is almost here! Microsoft plans to release SQL Server 2005 later this year and has packed the new database engine full of features.
Second Normal Form (2NF) - Databases Glossary
What is Second Normal Form? Find out here!
One-to-Many Relationships
Looking for a definition of one-to-many database relationships? Read our definition in the About Databases glossary!
Choosing a Primary Key
Databases depend upon keys to store, sort and compare records. If you’ve been around databases for a while, you’ve probably heard about many different types of keys – primary keys, candidate keys, and foreign keys. When you create a new database table, you’re asked to select one primary key that will uniquely identify records stored in that table.
Creating an ADO Connection
The first step in developing an ADO application is to create a connection to a data source. This tutorial walks you through the process.
Database Relationships
Looking for a definition of a database relationship? Check out the About Databases glossary definition!
Sample Excel Spreadsheet
This sample Excel spreadsheet provides a starting point for our Microsoft Access tutorials.
First Normal Form (1NF)
What is First Normal Form? Find out here!
Creating an Access Database
In an earlier article, we reviewed the process for creating an Access database from a template. While this is certainly an agreeable, easy approach to building a database, there isn’t always a template available that meets your needs. In this article, we review the process for creating an Access database from scratch.
Normalization
What is database normalization? Find out here!
Database Management System
A database management system (DBMS) is the software that allows a computer to perform database functions of storing, retrieving, adding, deleting and modifying data.
SQL Server Disaster Recovery
There are numerous threats to your data -- disk corruption, natural disaster, human error and server failure, among others. Is your disaster recovery plan sufficient to ensure your organization's interests are protected?
Adding Tables to Your Database
In Part 6 of our Building an Access Database From the Ground Up series, we’ll build the tables necessary to implement the relational structure developed in Part 4 that builds upon the Patrick’s Widgets scenario from Part 3.
HIPAA Privacy and Security
The Health Insurance Portability and Accountability Act of 1996 (HIPAA) places a large regulatory burden on organizations that deal with certain types of health-related information. We're now only a couple of weeks away from the compliance deadline for the Security Rule. Are you ready for April 21st?
Functional Dependency
What is a functional dependency? Find out here!
Access Queries
Part 9 of our Building an Access Database From the Ground Up series explores the use of queries to retrieve information from a database.
User Level Security in Access
If you’re a Microsoft Office power user, you might be familiar with the encryption features of Word, PowerPoint and Excel. These programs all allow file owners to easily apply encryption. Unfortunately, Microsoft Access doesn’t offer similar functionality, but it still has relatively powerful security functionality. In this article, we’ll take a look at Microsoft Access user-level security, a feature that lets you specify the level of access to grant each individual user of your database.
Two-Tier or n-Tier?
What's best for your situation? Two-tier, three-tier or n-tier databases? Find out here!
All About NULL Values
Users new to the world of databases are often confused by a special value particular to our field – the NULL value. Read about the proper uses of NULL in this article.
Timestamps in Microsoft Access
There are many applications where you may wish to add a date/time stamp to each record, identifying the time that the record was added to the database. It’s easy to do this in Microsoft Access using the Now() function. In this tutorial, I explain the process step-by-step.
Rational Access Templates
Zac Woodall's book provides an excellent introduction to creating and sharing Microsoft Access database templates. It's a wonderful reference for anyone who needs to occasionally or regularly design or develop Access templates.
Fourth Normal Form (4NF)
What is Fourth Normal Form? Find out here!
Print Mailing Labels in Access
One of the most common uses of a database is generating mass mailings. In this tutorial, we examine the process of creating mailing labels using Microsoft Access using the built-in Label Wizard. We begin with a database containing the address data and walk you step-by-step through the process of creating and printing your mailing labels.
Attribute
What is an attribute? Find out here!
SQL Server Tables Tutorial
SQL Server databases rely upon tables to store data. In this tutorial, we'll explore the process of designing and implementing a database table in Microsoft SQL Server.
Rollback
What is rollback? Find out here!
Query
What is a query? Find out here!
SQL Server
What is SQL Server? Find out here!
Modifying a Query in Microsoft Access
Want to learn how to modify a query in Microsoft Access? Find out on the About.com Databases site!
Microsoft Access Reports
Once you have information stored in your database, it sure would be nice to get it back out again! Part X of our Building an Access Database from the Ground Up series explains how to use reports to retrieve information from your database.
One-to-One Relationships
Looking for a definition of one-to-one database relationships? Read our definition in the About Databases glossary!
Microsoft Access
What is Microsoft Access? Find out here!
Starting a Career in Databases
Looking for a job in the database field? This article provides the advice you need to get started.
Online Transaction Processing
What is Online Transaction Processing (OLTP)? Find out here!
Access 2007
Microsoft might be competing against Oracle for market share in the server database category, but they maintain a clear lock on desktop databases with Microsoft Access 2007. The price tag may be a bit steep, but you won't find a more functional product anywhere. New bells and whistles in this version include a set of ready-to-go database templates to help you get a quick start and a vastly improved user interface that does away with the traditional toolbars and menus.
Column
What is a database column? Find out here!
Table
What is a database table? Find out here!
SQL Injection Attacks
One common type of database attack, the SQL Injection, allows a malicious individual to execute arbitrary SQL code on your server. Let's take a look at how it works by analyzing a very simple web application that processes customer orders.
Superkey
What is a superkey? Find out here!
Flat File
What is a flat file? Find out here!
Schema
What is a database schema? Find out here!
Access 2007 Books
So, you'd like to learn more about Microsoft Access 2007 and you don't know where to begin. I've selected five of my favorite introductory-level Access books for your perusal. Follow the "Compare Prices" links for a competitive listing of prices at various web merchants.
Oracle
What is Oracle? Find out here!
Backing Up Access Databases
Backing up your Microsoft Access databases is an important part of protecting your critical data. In this tutorial, we walk through the process of backing up an Access database, step-by-ste.
Retreiving Data with SELECT
The SELECT command is the most commonly used command in SQL. It allows database users to retrieve the specific information they desire from an operational database.
How To Install the Northwind Sample Database in Microsoft Access
Learn how to install the Northwind sample database in Microsoft Access.
NULLs and JOINs
JOIN operations allow us to combine data from multiple tables. Learn how these operations treat the NULL value.
Classification
What is classification? Learn about this data mining term here.
Database Instance
Looking for a definition of a database instance? Look no further!
Splitting an Access Database
Oftentimes, you wish to share data with users in your organization who may, in turn, wish to create their own forms and reports. While you may want them to have the ability to view and/or update your data, you may not wish them to modify the interface you use to work with the data yourself. Fortunately, Microsoft Access provides the ability to split a database into front-end and back-end components. You can safely share data with other users while keeping your interface private.
Backing up an Access Database
I've often been asked "How do I create a backup of my Access database?" Until now, that's been a difficult question to answer. Prior to Access 2003, you would have to manually copy your Access .MDB files into a secure storage location. That's all changed with Access 2003. In this tutorial, we'll walk through the process of backing up your Access database using the new built-in backup functionality.
Convert to Access 2007 Format
The ACCDB database format introduced in Access 2007 provides a number of enhanced features over the older MDB format. In this article, we'll walk you through the process of converting an MDB format database to the new ACCDB format.
SQL Server Data Types
Selecting appropriate data types is one of the most important considerations when designing a SQL Server database. Choices you make in the database design phase may have a significant impact on the efficiency, performance and storage requirements of your database down the road.
Stored Procedure vs. Function
SQL Server user-defined functions and stored procedures offer similar functionality. Both allow you to create bundles of SQL statements that are stored on the server for future use. This offers you a tremendous efficiency benefit, as you can save programming time by...
SQL Injection Testing
SQL Injection attacks pose tremendous risks to web applications that depend upon a database backend to generate dynamic content. In this type of attack, hackers manipulate a web application in an attempt to inject their own SQL commands into those issued by the database. In this article, we take a look at several ways you can test your web applications to determine whether they're vulnerable to SQL Injection attacks.
Many-to-Many Relationships
Looking for a definition of many-to-many database relationships? Read our definition in the About Databases glossary!
Repair Access Databases
Over time, Microsoft Access databases grow in size and unnecessarily use disk space. Additionally, repeated modifications to the database file may result in data corruption. Therefore, it's a good idea to periodically run the compact and repair database tool to ensure the consistency of your data.
Security Roles & Rights
Should businesses trust their employees with the critical role of protecting sensitive corporate information? Industry analysts would probably say “never” - and with good reason.
Access 2007 User Interface
If you’re switching to Microsoft Access 2007 from an earlier version, you’re bound to immediately notice some major changes in the user interface. Microsoft modeled the Access 2007 look-and-feel after the Windows Vista model, providing the application with a clean, high-tech look that could dramatically alter your workflow. In this article, we walk through the new interface. We’ll explore the Ribbon, the Microsoft Office button, the Navigation Pane and other features of Access 2007.
Clustering
What is clustering? Learn more about this data mining term here!
Date and Time Data Types
The date and time SQL Server data types are used to store calendar information. They include the datetime, smalldatetime and timestamp variables.
OCP Certification
Want to prove your Oracle Database Administration prowess to the world? Check out the Oracle 10g certification program!
Triggers
Triggers may be used to automate common database actions. Learn how to apply them effectively!
Create an Adobe PDF File
Adobe Acrobat (.PDF) offers a great method of sharing data across the Internet while preserving formatting. It's simple to generate these files from an Access database.
Microsoft ActiveX Data Objects
Microsoft ActiveX Data Objects (ADO) offer programmers a quick, easy way to access diverse data sources programatically.
Database
What is a database? Find out here!
Area Code Database
This free Access database of area codes provides database designers with a valuable tool to assist in mapping area codes to a state, province or region.
Creating Dynamic Web Pages with Microsoft Access
Want to create dynamic, server-generated HTML from your Access database? This step-by-step tutorial will walk you through the process.
Transactions
Database transactions allow you to group actions into atomic elements. Learn how to implement them in SQL.
SOUNDEX String Comparison
Can a filing system from the 1890s assist you with string comparison in modern databases? Read on!
Data Mining
What is data mining? Find out here!
E-mail Data Collection
Microsoft Access allows you to collect information from individuals and update your database automatically based upon their replies. Access includes a wizard designed to facilitate this task. In this tutorial, we walk through the process of populating an Access table with user-provided information.
Converting an Excel Spreadsheet to an Access Database
Are you ready to convert your unweildy Excel spreadsheet to a flexible Access database? Let us walk you through the process!
PHP
What is PHP? Find out here!
Online Analytical Processing
What is Online Analytical Processing (OLAP)? Find out here!
MCAS Access 2007
If you use Microsoft Access 2007 as a regular part of your job, or you hope to gain employment in the field of user-level databases, you may wish to consider the Microsoft Certified Application Specialist (MCAS) program's Access 2007 track. This program (formerly known as the Microsoft Office User Specialist or MOUS program) allows users of the popular desktop database to prove their knowledge in a structured exam environment.
MCDBA Certification
Interested in earning your Microsoft Certified Database Administrator (MCDBA) credential? Get off to the right start with this informative article!
SQL Server 2000 SP4
Are you running SQL Server 2000? Don't forget to keep it patched! Microsoft recently released Service Pack 4 which offers performance, security and servicability enhancements.
Character String Data Types
Character string data types are used to store text values in Microsoft SQL Server databases.
Record
What is a database record? Find out here!
Transact-SQL
What is Transact-SQL? Find out in the About Databases glossary!
Cursor
What is a Cursor? Find out here!
Show or Hide Access Tabs
Access 2007 introduces the tabbed document format found in other Microsoft Office products. In some cases, you may wish to hide these tabs to change the look and feel of your database or more closely simulate the appearance of older versions of Access.
Adding Splash Screens to Access
Splash screens add a custom flair to your Access database projects. Learn how to spice up your databases in this step-by-step tutorial

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