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ROW_NUMBER() Window Function – find duplicate values.

Many times, we do not want duplicate rows or values in our SQL tables. On the other hand, in some situations, it does not matter if there are duplicates present. For whatever reason, suppose duplicates have found their way into one of your tables. How can you find them quickly and easily? The ROW_NUMBER() Window function is a fantastic tool to use. Continue reading and see example queries you can apply to your own tables and find those duplicates…

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OS and DB used:

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Use MySQL BLOB column with PHP to store .pdf file

Like always I am sharing new things I learn here on my blog. I was recently working on a requirement for a LAMP stack web application reporting dashboard in which I needed to store – and eventually – retrieve a .pdf file. I have read in several places (this fantastic book is a great resource) that a viable option is storing images or documents (.pdf in this case) in the actual database table as opposed to on the server file system. MySQL has the BLOB datatype that can be used to store files such as .pdf, .jpg, .txt, and the like. In this blog post, I cover how I accomplished uploading and storing the actual .pdf file in a BLOB column in MySQL using PHP. Any corrections, tips, pointers, and recommendations for best practices are always welcome. We all learn as we go!!!

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MySQL DROP statement using phpMyAdmin

The MySQL DROP statement is one of many powerful DDL commands. Be it ALTER TABLE some_table DROP some_column or DROP some_table, this type of command can drastically change your data landscape because in executing MySQL DROP, you are completely removing objects from the database! If you are using the phpMyAdmin web interface, you can execute the MySQL DROP statement with just a few mouse clicks. Continue reading to see how…

Drops of water.

Self-Promotion:

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!

Note: The …

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Use phpMyAdmin to change column name and datatype in MySQL

Using the MySQL ALTER TABLE command, you can easily change an existing columns’ name and datatype. With just a few clicks, you can do the same in the phpMyAdmin visual web interface. For many developers, this interface is the one they lean on most while programming so it can’t hurt to know how to do it yourself should you find yourself programming in this environment…

Self-Promotion

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!

Suppose we have a table with these 3 columns:

  • id
  • title
  • grade

Our goal is to rename the title column to paper_title and to also change the datatype …

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MySQL Shell Python mode for multiple ALTER TABLE statements – easily

There may come a time you need to rename one or more columns in an existing MySQL table for a variety of reasons. Using ALTER TABLE, to rename a column is an easy enough command. But, suppose there are multiple tables in the same database/schema that have the same-named column and all of those columns need to be renamed. That could be a lot of ALTER TABLE statements to type out. Save your energy and time, avoiding all of those ALTER TABLE commands all-together. If you are lucky enough to be working with a MySQL version > 8.0 then the Shell is your salvation. With just a few lines of Python code in \py mode, all of your trouble(s) and headache(s) are no more…

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MySQL EXTRACT() method for specific DATE and TIME values

Date and time values are some of the most important datatypes in an RDBMS. From tracking order dates to payroll hours, DATE and DATETIME datatypes are used in all types of applications. At times as a Developer, you may need only certain portions of a DATE or DATETIME value. In MySQL, the EXTRACT() function can provide you with a specific component of a DATE or DATETIME value depending on which INTERVAL is given as a parameter. Continue reading to see example EXTRACT() queries for understanding…

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Dynamic MySQL CREATE TABLE statement with pandas and pyodbc

Have you ever had to type out a massive CREATE TABLE statement by hand? One with dozens of columns? Maybe several dozens of columns? There are likely some GUI tools to help with large CREATE TABLE commands. Or, other drag-n-drop types of software that I am not familiar with. What if you could write a few lines of Python code and take care of a huge CREATE TABLE statement with way less effort than typed manually? Interested? Continue reading and see how using pandas, pyodbc, and MySQL…

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OS, Software, and DB used:

  • OpenSuse Leap 15.1
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3 MySQL Commands Developers should know.

If you are a developer working in a MySQL environment, this blog post is for you. I share 3 MySQL commands or statements that you should know. That is a bold statement, I know. Turns out, once you do know (of) these commands, you will use them all the time. They minimize guesswork which leads to better productivity in other facets of your programming and querying workflow. I use them myself almost daily and am sure you will too once you see how simple they are to use. So why should you know them? Continue reading and find out…

Photo by hannah joshua on Unsplash

OS, Software, and DB used:

  • OpenSuse Leap 15.1
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TRIM() string function in MySQL – with examples.

In this post, I’ll cover examples of the MySQL TRIM() function. TRIM() removes specific characters – or spaces – from a given string, at either: the beginning, ending, or potentially in both locations depending on several factors. With an optional keyword argument that controls which character(s) – if any – are removed, TRIM() can be tricky so let’s gain understanding with several easy-to-digest examples…

Photo by Peter Beukema on Unsplash

OS, Software, and DB used:

  • OpenSuse Leap 15.1
  • MySQL 8.0.20

Self-Promotion:

If you enjoy …

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Sorting associative arrays in PHP with array_multisort() – New learning

If you write MySQL queries, at some point you are going to have to provide query results in a specific order. To impose any ordering in MySQL (this applies to SQL overall and is not directed only at MySQL), you have to use the ORDER BY clause. Without it, there is no guaranteed order. The database is free to send back query results in any order. As I learn PHP, I make it a point to explore both the MySQL side, along with the PHP side in regards to similar type tasks and the efficiency of each. So far in my PHP journey, I have found that arrays are used quite extensively. In this post, I’ll cover array_multisort() – one of many in-built PHP functions – used for sorting arrays. In the context of the example data for this post, the arrays are populated by an unordered MySQL query. Let’s see one example of how you can establish a sorting order in a PHP …

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