Databases Archives - Life Beyond Tech

What is Referential Integrity?

November 18, 2018March 29, 2024 Andrew Comeau

One of the fundamental differences between an Excel spreadsheet and a Microsoft Access or SQL Server database is the database’s ability to group data by subject into tables and create links between that information. This type of organization enables the user to store large amounts of data and retrieve specific information quickly by writing queries that will search on the various fields. Referential Integrity is actually a simple but essential concept to understanding how databases like Access or SQL Server work. Once you understand it, you will be able to use these tools to better organize and report on your data.

To demonstrate this concept, I’m going to use a few tables in a Microsoft Access database. Access is a great environment to start learning about databases as it provides a user-friendly interface and is widely available through Office365.

Watch the companion video for this article on YouTube or continue article below …

Database Design, Microsoft Access

Performing a Basic Install of MySQL or MariaDB in Windows

May 21, 2017February 18, 2023 Andrew Comeau

One of the great things about MySQL and MariaDB are their versatility of installation. They can be setup as a Windows services and trimmed out with some extra utilities or it can be installed on a flash drive as a portable server.

The easiest installation is certainly the Windows Installer with a wizard for MySQL or the MariaDB MSI that will guide you through the installation of the server and all the options you want. Myself, I still like self-contained programs that won’t interfere with anything else on my system and can be easily removed without leaving hidden traces. I also don’t like adding a lot of stuff to my Windows startup.

If you have a basic comfort with using the Windows command line and control panel, doing a minimal installation of either MariaDB or MySQL is not difficult once you understand a few steps. The MySQL full documentation and the MariaDB Knowedgebase are available for reference on their respective sites but here are the essentials to get you started.

Database Design, How-to

Calculated Fields in CiviCRM

June 14, 2016December 27, 2022 Andrew Comeau 2 Comments

One of CiviCRM’s strengths is the ability to add custom fields to hold specific information about your contacts. One thing it doesn’t offer (yet) is a calculated field type that will present the results of calculations of other fields. While calculated fields are generally discouraged in relational database design, they are sometimes necessary within a user interface. One suggested method is to add custom code hooks within CiviCRM’s PHP code but as a database guy, I decided on a back-end solution.

Database Design, Programming, SQL

MySQL User Defined Function Example: Data Cleanup

May 23, 2016July 13, 2026 Andrew Comeau

(Updated June 9, 2016)

The Challenge

One of my current projects involves migrating a large amount of data away from an old custom Borland Paradox application into a new CiviCRM system. As with too many quickly-constructed apps, this old Paradox database wasn’t especially well designed and, among other the other challenges in salvaging the data, there were no restrictions on how dates could be entered. This means that, in multiple fields within each of the 20,000+ database records, I might see any of the following:

03-14-96
5/20/1975
10/02/83
09051975
07.19.1995
19830211121500

While CiviCRM does have a utility for importing data from CSV and other SQL tables, it was having quite a time with this collection and many of the dates were being mishandled. That’s if the records weren’t rejected entirely for other reasons. Data migration doesn’t often happen with just a few settings adjustments and a click of the Import button.

Database Design, MySQL, Programming

Installing MySQL on Mac OS X El Capitan

February 23, 2016February 18, 2023 Andrew Comeau

A few months ago, I wrote about how to install MySQL on Windows with IIS. Now I want to show you how to create an AMP web programming stack (Apache, MySQL & PHP) on Mac OS X. As with Windows, you could just go with a ready-made development environment like MAMP but, if you’re going to be doing real database and web design work with MySQL, it’s best to know how everything works.

Background

For this demonstration, I’m going to be using Mac OS X El Capitan (v.10.11), the latest version as of this writing. My installation environment is a hosted Mac server with 1 GB of RAM and 40 GB of disk space. I will be demonstrating the process using the Terminal commands.

Unlike Windows, OS X already includes the Apache web server and PHP language pre-installed so it’s a much simpler process to ensure that everything is working together. You will need root access in order to install and configure the components.

Database Design, Software

Splitting a Database in Microsoft Access

February 10, 2016April 23, 2024 Andrew Comeau

Microsoft Access is unique among all of the Microsoft Office applications in that it can be used to create entire applications that contain large storehouses of data, versatile data entry forms and sophisticated reports to present the data in a variety of ways. It also goes beyond other applications such as Microsoft Excel in that a single database is able to store and organize large amounts of data from different sources and on different subjects while enabling many users to easily find and work with that data as needed. While an Excel spreadsheet is excellent for analysis and can provide access to multiple users, Access takes it a few steps further and enables users to store and manage volumes of data and present it in many different ways based on the needs of the data users and the intended distribution.

Why Split a Database?

The multi-user environment provides its own challenges. Access is often used as an ad hoc development tool by people outside the I.T. department to design needed solutions that would otherwise have to be purchased for large amounts of money. These applications can end up being used by many people across a company and that means there can be many people accessing the same database file at the same time. If enough people are in the file at once, the performance of the application can degrade pretty quickly. Also, when one person has the database file open, the file is then read-only for anyone else who opens it which means that they will be unable to create or edit their own reports or database queries.

Microsoft Access

“Microsoft Access has stopped working” – fixing corrupt files

January 18, 2016July 13, 2026 Andrew Comeau

Summary Occasionally, when you’re making a lot of design changes to a Microsoft Access database, Access might start crashing when you’re working with that specific database file or when trying to enter the VBA environment with ALT-F11. This leaves you unable to investigate the issue or make further changes. It can be a sign that there are errors within the project’s…

Database Design, Microsoft Access

Adding Passswords to Microsoft Access Switchboard Options

November 2, 2015July 13, 2026 Andrew Comeau 1 Comment

The Switchboard Manager in Microsoft Access makes it easy to create a system of menus that will enable your users to navigate through your application. It also relieves you of the need to manage multiple menu forms and macro calls.

Microsoft Access switchboard form — Figure 1 – Example Access Switchboard

Sometimes, however, you might want to keep all but a few users out of specific areas, even if it’s just a password to discourage the curious. This is one thing the Switchboard Manager doesn’t offer and I’d like to show you one method for achieving this here. I want to stress that this method is not truly secure. On it’s own, it won’t prevent a user from hitting F11 and browsing through the database. A power user who wants to see those areas could defeat this method pretty quickly. It will keep the merely curious and inexperienced users out, however, and could be combined with other measures to add more security.

How-to, Microsoft Access, Programming

Using Visual Studio to Manage Your Data

December 23, 2014April 23, 2024 Andrew Comeau

(This article was updated in August 2018 for use with Visual Studio 2017.)

Moving Beyond Microsoft Access

I’ve written a lot about Microsoft Access over the years and still believe it’s a great training ground for people who want to learn to design database applications. Its user-friendly interface provides an easy learning curve and introduction to the basics of relational databases, data entry forms and report design. If you want to get serious about programming, however, it’s important to expand your skillset beyond Access with tools that are in demand by potential employers and customers.

One of these tools is Microsoft Visual Studio, the development suite that provides access to the .NET family of languages including C# and VB.NET. With Visual Studio, you can create a variety of professional applications from Windows form applications to websites powered by ASP.NET. While Microsoft Access provides some impressive tools for the office power user and even some full-time programmers, Visual Studio is the next step up the development ladder. It enables professional programmers to design any type of solution without being tied to a Microsoft Office installation and without the limitations of the Windows desktop. A couple quick searches of sites like CareerBuilder.com will show you the kind of jobs and salaries that knowledge of Visual Studio can lead to as opposed to Microsoft Access.

Microsoft Access, Programming

SQL Server for Beginners: Part V – Using SQL Server 2012 LocalDB

April 18, 2014December 30, 2025 Andrew Comeau

On request, I’m reposting this series of articles on SQL Server. I have reviewed them for any obvious issues but please remember that these were written in 2014 and may not always reflect the current technology. See the official Microsoft page for more information on the latest version.

In a previous chapter, I described the installation process for SQL Server 2012 Express which included all the bells and whistles of the advanced services package. While it’s great to have all the tools at your disposal to learn from, some people might not want such a large installation on a particular machine or the administration that goes with it but might still want the basic database capabilities of SQL Server on their desktop. In this case, SQL Server 2012 offers a new edition called LocalDB.

LocalDB is a minimized version of SQL Server Express specifically for developers who still need all the programming features including the ability to create stored procedures and other objects within an instance of SQL Server. It has a few restrictions that the average beginner probably won’t be bothered by and you can connect to it with SQL Server Management Studio (SSMS) or other tools to create and manage databases. You can even install the AdventureWorks sample database to work with through an instance of LocalDB.

In this article, I’ll describe the process of installing both LocalDB and SSMS in order to create a small desktop database environment to work with as a developer or a beginner in database design.

Articles, Database Design, SQL