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Displaying posts with tag: MySQL Developer (reset)
MySQL Self-Join

I’m switching to MySQL and leveraging Alan Beaulieu’s Learning SQL as a supporting reference for my Database Design and Development course. While reviewing Alan’s Chapter 5: Querying Multiple Tables, I found his coverage of using self-joins minimal.

In fact, he adds a prequel_film_id column to the film table in the sakila database and then a single row to demonstrate a minimal self-join query. I wanted to show them how to view a series of rows interconnected by a self-join, like the following:

SELECT   f.title AS film
,        fp.title AS prequel
FROM     film f LEFT JOIN film fp
ON       f.prequel_id = fp.film_id
WHERE    f.series_name = 'Harry Potter'
AND      fp.series_name = 'Harry Potter'
ORDER BY f.series_number;

It returns the following result set:

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MySQL Client in 8.0.21+

Having recently installed a fresh copy of MySQL 8.0.21 on Windows, I took careful note of parsing changes in the MySQL Shell. It was tedious that we lost multiple statement processing, which is supported in the MySQL Client and MySQL Workbench because it uses MySQL Client.

It was frustrating when I subsequently discovered that the MySQL Shell took away the ability to write log files by removing the TEE and NOTEE commands. I suspected that since MySQL Workbench was still using the MySQL Client that it should be in the code tree. In fact, the mysql.exe client is in this directory:

C:\Program Files\MySQL\MySQL Server 8.0\bin

So, I immediately created a batch file to put the MySQL Client into my %PATH% environment variable when needed. I used this time tested DOS command: …

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Conditional Updates

While I’m switching labs next term after more than a decade with more comprehensive lab set, I’m hoping the new exercises build the students’ core SQL skill set. Next term, I hope to see whether the change is successful. I’ve opted for using Alan Beaulieu’s Learning SQL: Generate, Manipulate, and Retrieve Data, 3rd Edition, because it’s a great book and uses the MySQL database.

One exercise that the students will lose is a data migration exercise from a badly designed common_lookup table to a well designed common_lookup table. The starting point is shown below on the left and the fixed version is on the right.

         …

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MySQL Shell Parsing

I’ve been experimenting with the mysqlsh since installing it last week. It’s been interesting. Overall, I’m totally impressed but I did find a problem with how it parses stored procedures.

First thought is always, is it my code? I checked the file by running it as a script file through MySQL Workbench. It ran perfectly in MySQL Workbench but failed repeatedly when run from the mysqlsh utility. Next step, reduce the code to a small test case, retest it, and log a bug if it is replicated. My test case in a test.sql file generates the following errors when run from the mysqlsh utility:

 MySQL  localhost:33060+ ssl  studentdb  SQL > source test.sql
Query OK, 0 rows affected (0.0003 sec)
ERROR: 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the …
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MySQL Unicode Warning

It’s always interesting when I upgrade from one release to the next. I learn new things, and in the case of MySQL’s installation and maintenance I become more grateful for the great team of developers working to produce MySQL 8.

A warning that caught my eye in MySQL 8 (8.0.21) was this one on Unicode with the utf8 character code:

Warning (code 3719): 'utf8' is currently an alias for the character set UTF8MB3, but will be an alias for UTF8MB4 in a future release. Please consider using UTF8MB4 in order to be unambiguous.

Currently, a character alias for utf8mb3 is an alias for the deprecated utf8mb3 (a 3-byte character set) until it is removed. When the utf8mb3 character set is …

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MySQL Configuration

I’ve been using MySQL 8 on Linux for a couple years but the Linux repository version didn’t install the new MySQL Shell. So, I discovered the new MySQL Shell when I installed MySQL 8 (8.0.21) on Windows to teach my student how to use it to learn SQL commands. I encourage you to read the full MySQL Shell document.

The following is a tutorial to provision a student user and studentdb database in MySQL. It uses the MySQL Shell (mysqlsh) and stages for uploads of comma-separated values files.

After installing MySQL on the Windows 10 OS, open the Window OS Command Line Interface (CLI) shell by entering the following in the search field at the bottom left:

cmd

It launches a CLI interface to the Windows OS. The cmd (command) utility opens the CLI in the following …

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MySQL File Privilege

While preparing a set of student instructions to create a MySQL 8 (8.0.21) Windows 10 instance I found an error with LOAD command and the --secure-file_priv variable set in the my.ini file. After granting the global FILE permission to the previously provisioned student user:

GRANT FILE ON *.* TO 'student'@'localhost';

Any attempt to run the following command failed:

LOAD DATA INFILE 'C:\ProgramData\MySQL\MySQL Server 8.0\Uploads\avenger.csv'
INTO TABLE avenger
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
ESCAPED BY '\\'
LINES TERMINATED BY '\r\n';

and, raise this error message:

ERROR: 1290: The MySQL server is running with the --secure-file-priv option so it cannot execute this statement

The following covers my exploration to try and fix this error without removing a designated directory for secure file uploads. While MySQL 5.7 …

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MySQL 8.0 Install

MySQL will be used for our online sections because the VMware instance and Docker configurations where too large to effectively download this term.

MySQL 8.0.21 Installation Steps

After you download the MySQL 8 MSI file, you will perform the following 24 steps to install MySQL on Windows 10. If you want a full developer install you must install Microsoft Excel and Visual Studio first.

  1. The first thing you need to do is grant privileges to allow the MySQL Installer application to work in Windows 10. Click the Yes button to authorize the MySQL Installer to run.

  1. The next thing you need to do is grant privileges to allow …
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MySQL Server-side

A student question: Does JavaScript make context switching for web-based applications obsolete? Wow! I asked what that meant. He said, it means JavaScript replaces all other server-side programming languages, like PHP, C#, or Python. I asked the student why he believed that. His answer was that’s what two interviewing managers told him.

I thought it would be interesting to put the idea to a test. Below is a Node.js script that acts as a utility that queries the MySQL database with substitution variables in query. It also returns a standard out (stdout) stream of the MySQL query’s results. It also supports three flag and value pairs as arguments, and optionally writes the results of the MySQL query to a log file while still returning result as the stdout value. All errors are written to the standard error (stderr) stream.

The Node.js solution is completely portable between Windows …

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Express.js & MySQL

Sometimes, you just half to chuckle. A couple folks felt that I didn’t give enough information in my post showing how to configure a small Node.js application that could access a MySQL database. Specifically, they wanted me to explain the following:

  1. Configure your Express.js and MySQL development in a single Node.js application.
  2. How to convert the list of RowDataPacket objects as elements of data, which is really just simple JavaScript knowledge.
  3. How to bind variables into the query.

Like the other blog post, this one assumes you’ve performed a global install of Node.js on a Linux server. If you’re unfamiliar with how to perform a global Node.js installation, I cover how to do it in this …

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