MySQL roughly random string generation for inserting or updating rows

Ever wanted to inject hashes into new or existing rows of a MySQL database?

Two slightly different methods, but the same result…

Insert

The code below allows you to generate a different hash for each row you’re inserting. You can tweak to choose the string’s length. No unique checks are done.

INSERT INTO table_name (
column_name
) VALUES (
    (SUBSTRING(MD5(RAND()) FROM 1 FOR 20))
)

Update columns and values to suit your needs

Update

The code below allows you to generate a different string for each row affected by the update and choose the random string’s length from 1 to 32 character.

I’m aware it’s not the most random of generators but for url hashes etc, it works well. Be sure to then check for duplicates, which are possible!

Change 20 to a length between 1 and 32 that suits your needs.

Update the WHERE condition to suit your needs

UPDATE table_name
SET column_name = (
    SELECT substring(MD5(RAND()), -20)
)
WHERE condition_column = 1;

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Add global Twitter Bootstrap modal listeners

If you’re ever browsed the Twitter Bootstrap javascript documentation then you’ll know that the modal parts of the Bootstrap library require some javascript to show and hide them.

Part of the javascript is related to events which you can attach listeners to so you know when your modal shown and hidden.

What they don’t tell you is that you can add a single global (or semi global if you want) listener to all modal events which will fire when any modal is shown or hidden.

$('body').on('shown', '.modal', function () {

	console.log('we have shown a modal');

});

For example the above will console log “we have shown a modal” when any modal is shown. You can switch the shown event to be show, shown, hide or hidden.

Fix apache after upgrading to Mountain Lion

Every time I upgrade OS X something breaks with apache or php or both.

The steps for me to fix it this time was…

* Open your httpd.conf file
* uncomment the Load php5 module
* uncomment the load vhosts module

in etc/apache2/users

* duplicate Guest.conf to harrybailey.conf – replace harrybailey with your username obviously
* edit harrybailey.conf to read:

<Directory "/Users/harrybailey/Sites/">
    Options Indexes MultiViews
    AllowOverride All
    Order allow,deny
    Allow from all
</Directory>

Note: as Michal mentions below you may want to add +FollowSymLinks to your options too. This allows the system to follow any symbolic links you have set up.

AGAIN – replace harrybailey with your username.

* save the file

You may also get a php error which includes…

“It is not safe to rely on the system’s timezone settings”

The fix for that is
* navigate to /etc/ and rename php.ini.default to php.ini
* edit your new php.ini file – find “;date.timezone = ” (no brackets)
* update it to read “date.timezone = Europe/London” (no brackets) – if you aren’t on GMT then find your relevant timezone string and use that
* save the file

* open terminal
* submit the line:
sudo apachectl restart

That did it for me. Hopefully it will do it for you too.

I was first seeing the default html file in the /Library/Webserver/Documents folder
I was then seeing 403 errors for all vhosts that I has setup
Personally I saw these problems after upgrading from Lion (10.7) to Mountain Lion (10.8)

Export structure and data from Navicat Premium as SQL

I was trying to find the quickest way to export both structure and data from all tables of a database from Navicat Premium and came up with these steps:

* Use the backup tool to create a backup of your database
* Right click the backup and select to Extract SQL…
* Save to wherever you like

You can now use that .sql file to create a new database wherever you like.

Yii (and Yii2) wildcard / catch all url rules

Both Yii and Yii2 have url management and routing built in. They will compare the url of the request to a list of rules you’ve defined.

Sometimes you might want to do various checks of the url in yii config main and then send every other request to a particular controller.

The rule you need to add last to the urlManager is…

'(.*)' => 'controller/action',

… and now any rule that isn’t matched previously will end up being sent to your defined controller and action.

In Yii2 you can also do the same:

'<url:(.*)>' => 'controller/action'