Marek

SQL Tip – CONVERT_TZ in MySQL

Working with time zones has generic and platform-specific challenges. This SQL tip involves some design aspect not only the specific SQL code. Namely taking care to have a method to determine the original local used to create the date time entry.

Design Tip – None or NA Instead of NULL

We are working in a world of existing applications with known technical issues couple with development and business techniques that emphasize moving quickly to fail quickly and learn from the mistake. Now that does not mean you should be selectively ignorant when beginning a new design and forget all the fundamentals. If you are theContinue reading “Design Tip – None or NA Instead of NULL”

SQL Tip – Working With the UNION Clause

I have been working with the SQL language for very many years. I take for granted that most developers are not very experienced in using commands outside of simple select, insert, update and delete statements. Certainly, this can be a disadvantage… (Click for more)

Definition – Database

In order to have an accurate and reliable data for effective decision making you need to record the various details. These details can be used to model a process that captures the essential properties of the data. It is useful but not always essential to perfectly relate or define the data. This collection of organizedContinue reading “Definition – Database”

SQL Tip – Update Many Records in One Table With Another

I did not wait a long time for the inspiration to write this next tip. The update statement can be confusing if you are not writing SQL on a regular basis. I will explain how to update a table with the records from another table… (Click for more)

SQL Tip – Finding Duplicate (or Having)

Most developers have a basic knowledge of the SQL commands “Select,” “Insert,” “Update” and “Delete.” Sometimes you want the database to return something different than was initially planned and that is when you need the SQL statements to do more. Being asked to find duplicates is a request that comes up repeatedly.

Design tip – Enumeration vs. Lookup

I wanted to provide a simple list of good practices for database design. As I started writing, I realized that the article would be very voluminous and difficult to write at once. So, I picked a single topic that I think the developer will eventually need to think about.
In my experience, the enumerated type in a platform solves one or more problems for the developer. So as the developer notices this possibility, they simply ask…

What this site will be about?

Welcome to my blog SQL Clinic. SQL Clinic is a blog that serves the application developer community with tips about the SQL language, configuring databases and database design tips. I hope, eventually, that the information that I provide is helpful when looking for solutions and insightful when thinking about new designs.