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!!!
Database Programming
Use MySQL UNIQUE Constraint in phpMyAdmin
The MySQL UNIQUE constraint is often used in a column definition in which we need each value for that column to be distinct from the others. Perhaps it is an email column for an on-line registration form and we want to ensure that users cannot register twice for an account using the same email. Whatever the case may be, UNIQUE is there to help us ensure this type of data integrity or business requirement. What if the target table already exists and you determine you need to add a UNIQUE constraint to an existing column? In this post, I will cover 2 ways you can implement a UNIQUE constraint on existing columns using the phpMyAdmin web interface…
Basic Data Analysis with MySQL Shell Python mode
I recently watched a fantastic Python Pandas library tutorial series on YouTube. Without a doubt, Pandas is great for all sorts of data stuff. On the same token, MySQL Shell in Python mode is quite powerful in the sense that Python and the MySQL Shell (version >= 8.0) are somewhat united in the same environment. Although Pandas is in a league all its own when it comes to data analysis, between the power of MySQL and Python, we can also perform some basic analysis easily in MySQL Shell Python mode. In this blog post, I will cover some basic data analysis using Python mode in the MySQL Shell. Continue reading to see examples…
[Keep reading for more MySQL database and Python/PHP-centric content >>>]PHP PDO lastInsertId() method with examples in MySQL
MySQL has an AUTO_INCREMENT column attribute which automatically generates a consistent integer value upon a successful (or not) INSERT. Oftentimes, this attribute is set on a column deemed the PRIMARY KEY. Therefore, providing a unique value for the column and ensuring each rows’ individual identity. The LAST_INSERT_ID() function returns the most recently generated value for a column with the AUTO_INCREMENT attribute. Many times, you use this value further in query processing (E.g., link a newly signed-on customers’ information to a joining table of orders, ensure referential integrity between parent and child tables using a FOREIGN KEY and PRIMARY KEY, INSERT into another related one-to-one table, etc…). The PDO PHP library has a like-named class method, lastInsertId(), which provides the same functionality as LAST_INSERT_ID() in a PHP context. In this post, I’ll visit lastInsertId() with a simple example. Continue reading to learn more…
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…