Sometimes it is critical to ensure a group of queries are all executed successfully to maintain the integrity of our data. Let's say we have a banking app where we need to subtract funds from one account and add funds to another:


$mysqli->query ("UPDATE 'accounts' SET 'balance' = 'balance'-1000000 WHERE 'user' = 'Bob'");
$mysqli->query ("UPDATE 'accounts' SET 'balance' = 'balance'+1000000 WHERE 'user' = 'Fred'");

What if one of the queries fails? To mitigate the chances of misplacing our millions due to some possible error we must ensure that both queries are executed with the expected result before committing any changes to the data. This where transactions are useful. We can run the queries, then check if some conditions are met before committing the changes in the data:


What?
A quick article on how to trim in MySQL along with getting rid of any leading or trailing tab characters.

Why?
I use MS Excel for organizing data and then converting to MySQL commands. Unfortunately, the MS Excel software adds tab characters to delimit the columns...

How?
UPDATE `mytable` SET `myColumn` = TRIM(CHAR(9) FROM TRIM(`myColumn`));
Source: Stack Overflow - How to Remove Tabs

What?
A quick article showing my MySQL statement when I want to remove all the accents from foreign characters and return the English equivalent.

Why?
A content management system (CMS) that I'm working on has just gone international and started including the names of places in other countries. This is nice but its search engine doesn't work properly as it thinks "riviere" is different to "rivière". We need to ensure that a search for any of these kind of words will return results of similarly typed/sounding words.

How?
Here's just a splurge of SQL but I use this often enough:

What?
A quick article on how to populate a database column from another table using a string comparison.

Why?
I have several database tables which replicate country names and I would rather they all use the ccTLD two letter code. This article was written because it took me so long to work it out.

How?
UPDATE  `table_to_update` a
        INNER JOIN `table_to_read` b
            ON a.`CountryName` COLLATE utf8_general_ci LIKE b.`CountryName` COLLATE utf8_general_ci
SET     a.`ccTLD` = b.`ccTLD` 

Applies to:
  • MySQL Database v5.0.45
  • MySQL Workbench v6.0.8.11354 build 833

What?
This is a quick article on how to get around the problem of backing up your MySQL database when attempting to "Data Export" using MySQL Workbench. This is not regarding the connection issue as I can connect to my database using MySQL Workbench (I have enabled the old authentication protocol). The error ONLY appears when I try to "data export" the database.

Why?
The quick solution for everyone else is to change/reset the password of the connecting database user, but herein lies the problem. When you read my workaround, you'll say that I haven't solved anything; but this is a production database I want to export for offline backup. I have to raise and log a formal change request and follow a workflow process in order to make a change on a live system to a service user account... Especially one used by the scripts to access the database-driven website.

How?

What?
So this is an article exploring how to convert UPPERCASE text into mixed case. The feed is originally for a personnel feed so it won't be converting long paragraphs of English text. Instead it will be applied to names and addresses as well as job titles and departments.

Why?
We wanted a T-SQL version despite having successfully built a custom script component for SSIS.

How?
You can search my site for how to do this in VB or C#. This version is entirely using T-SQL and we're going to use a function so no dynamic SQL (execute, evaluate).

Related Articles

Joes Revolver Map

Joes Word Cloud

page   note   database   form   time   table   server   need   used   error   name   joomla   mysql   file   version   work   select   system   files   where   script   report   example   first   google   solution   user   find   html   data   source   windows   display   would   parameter   uploaded   could   value   using   license   following   date   code   zoho   program   list   website   search   site   added   JoelLipman.Com

Accreditation

Badge - Certified Zoho Creator Associate
Badge - Certified Zoho Creator Associate

Donate & Support

If you like my content, and would like to support this sharing site, feel free to donate using a method below:

Paypal:
Donate to Joel Lipman via PayPal

Bitcoin:
Donate to Joel Lipman with Bitcoin - Valid till 8 May 2022 3QnhmaBX7LQSRsC9hh6Je9rGQKEGNQNfPb
© 2021 Joel Lipman .com. All Rights Reserved.