mysql – Row Coding

CodeIgniter: Unable to connect to your database server using the provided settings Error Message

by Tarik

I think, there is something wrong with PHP configration. First, debug your database connection using this script at the end of ./config/database.php : … … … echo ‘<pre>’; print_r($db[‘default’]); echo ‘</pre>’; echo ‘Connecting to database: ‘ .$db[‘default’][‘database’]; $dbh=mysql_connect ( $db[‘default’][‘hostname’], $db[‘default’][‘username’], $db[‘default’][‘password’]) or die(‘Cannot connect to the database because: ‘ . mysql_error()); mysql_select_db ($db[‘default’][‘database’]); echo …

Why does PDO print my password when the connection fails?

by Tarik

You should have display_errors = off in your PHP.ini anyway to avoid this problem. Errors that reveal details like these come from many places, in addition to PDO. Yes, you should also have it in a try/catch block. You can also $pdo->setAttribute(PDO::ERRMODE_SILENT), but then you need to be checking the error codes manually rather than …

Find total number of results in mySQL query with offset+limit

by Tarik

Take a look at SQL_CALC_FOUND_ROWS

Get query back from PDO prepared statement [duplicate]

by Tarik

Try $statement->queryString.

Is it possible to query a tree structure table in MySQL in a single query, to any depth?

by Tarik

Yes, this is possible, it’s a called a Modified Preorder Tree Traversal, as best described here Joe Celko’s Trees and Hierarchies in SQL for Smarties A working example (in PHP) is provided here http://www.sitepoint.com/article/hierarchical-data-database/2/

What does ON UPDATE RESTRICT do?

by Tarik

RESTRICT prevents the action from happening if there’s any foreign keys that rely on the field that’s being changed.

Handling very large data with mysql

by Tarik

Can MySQL reasonably perform queries on billions of rows? — MySQL can ‘handle’ billions of rows. “Reasonably” depends on the queries; let’s see them. Is InnoDB (MySQL 5.5.8) the right choice for multi-billion rows? — 5.7 has some improvements, but 5.5 is pretty good, in spite of being nearly 6 8 years old, and on …

Doing calculations in MySQL vs PHP

by Tarik

I’d play to the strengths of each system. Aggregating, joining and filtering logic obviously belongs on the data layer. It’s faster, not only because most DB engines have 10+ years of optimisation for doing just that, but you minimise the data shifted between your DB and web server. On the other hand, most DB platforms …

How to find out the username and password for mysql database

by Tarik

Go to this file in: WampFolder\apps\phpmyadmin[phpmyadmin version]\config.inc.php Usually wamp is in your main hard drive folder C:\wamp\ You will see something like: $cfg[‘Servers’][$i][‘user’] = ‘YOUR USER NAME IS HERE’; $cfg[‘Servers’][$i][‘password’] = ‘AND YOU PASSWORD IS HERE’; Try using the password and username that you have on that file.

results grid not showing on mysql workbench 6.3.9 for macOS sierra

by Tarik

Good News! 😃 Apparently this is a widespread bug on macOS High Sierra that was fixed in version 6.3.10 that was released Nov. 15th 2017. They fixed it as described in the release notes: https://dev.mysql.com/doc/relnotes/workbench/en/wb-news-6-3-10.html Executing a query in MySQL Workbench on a host running macOS High Sierra failed to load the result grid completely, …