Sometimes when querying SQL tables, you wish to find rows that are missing as opposed to the rows which are present. In this post, I’ll demonstrate 2 queries you can use to determine rows that are present in one table but missing in another table…

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Note: For the example queries in this post I am…


Suppose you have a comma-separated list composed of numbers and you want it sorted in order from smallest to largest. Continue reading and see a working example I came up with as I continue studying Oracle SQL…

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Note: As with anything, just because you can do something doesn’t necessarily mean you should do it. This…


Although I primarily work with MySQL/MariaDB these days on back-end web development projects, I am studying Oracle SQL with the end goal to become certified. I recently watched a great YouTube video and decided to try my hand porting over the Oracle SQL queries to comparable MySQL for a learning exercise. This blog post details the queries I came up with for the end results. Continue reading for some fun recursive CTE’s using the SUBSTRING() character function and interesting output display variations.

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As an SQL professional or developer, at some point, you’re going to encounter the infamous value NULL (or marker as some say). NULL‘s can be super tricky to get right until you halfway understand them. Fortunately, all the popular SQL vendors have various functions in place that help work with NULLs. In this post, I cover 2 such functions found in the Oracle database, NVL() and NVL2().

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As always, I am sharing what I learn here on my blog. As I continue to study SQL, the language never ceases to amaze me with those little intricacies you don’t necessarily learn of unless you are bitten by them, or through intentional study. Luckily, my case is the latter of the 2. I’m referring to the ORDER BY clause when used in GROUP BY queries. Continue reading for more information.

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There are a number of reasons why you may need to rename a table in your SQL Database. Whatever the case may be, the process is super-easy. In this post, I share 2 different ways you can rename an existing table in the Oracle Database.

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Nothing beats real-world experience in programming. Actually, pretty much everything in life is learned through experience.

I was recently implementing a feature in a LAMP stack web application and ran into a sharp edge when filtering a MySQL query by DATETIME column values using the BETWEEN operator.

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I was under the impression that BETWEEN is inclusive, meaning that any values within the specified ranges, along with those matching both the high and low-end ranges themselves, would also be included in the returned result set.

BETWEEN is inclusive. However, as I discovered, a DATETIME column data type acts somewhat unexpectedly, when…


I recently wrote a couple of blog posts on the SQL CASE expression with examples in MySQL. As I study and learn more about Oracle SQL, I wanted to apply a CASE expression to the RPAD() character function for dynamic string padding. Continue reading to see an example query…

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If you enjoy the content written here, by all means, share this blog and your favorite post(s) with others who may benefit from or like it as well. Since coffee is my favorite drink, you can even buy me one if you would like!

The SQL CASE expression is so…


The INSERT DML command introduces new rows of data into an SQL table. INSERT is under the Create domain of the CRUD acronym. When using the Oracle SQL Developer IDE, instead of writing a INSERT INTO command, there are visual elements within the IDE interface that help facilitate an INSERT operation. Continue reading to learn how with a simple example…

Choose Table To Insert Data Into

In the left-hand pane of SQL Developer (not shown) double-click on the table, you want to INSERT data into. A new dashboard will appear containing several different tabs.

Shown below are the dashboard view and table description for table STAGE_WALKING_STATS::


If you’re working with Oracle SQL and need to load CSV data into one of your tables, using Oracle SQL Developer makes this process a breeze. Continue reading to see a simple example and learn how…

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If you enjoy the content written here, by all means, share this blog and your favorite post(s) with others who may benefit from or like it as well. Since coffee is my favorite drink, you can even buy me one if you would like!

I have written quite a few blog posts about CSV’s in an SQL context (some in a Python environment…

Joshua Otwell

SQL and PHP/CodeIgniter Developer. Growing through Technical Writing and Blogging my journey and passion at https://joshuaotwell.com

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