PHP-Scripts Blog » MySQL

How to use MySQL REPLACE function

TDavid — Wed, 14 Mar 2007 17:02:43 +0000

Here’s a MySQL query fuction that’s easy to forget about: REPLACE. Let’s say I have a bunch of records in a field with http://www and want to quickly change all to http://. Here’s the syntax to update:

UPDATE tdurl_1 SET URL = REPLACE(URL, ‘http://www.tdurl.com/’,'http://tdurl.com/’);

Open source phpMyEdit

TDavid — Sun, 12 Nov 2006 14:08:29 +0000

phpMyEdit:

generates PHP code for displaying/editing MySQL tables in HTML. All you need to do is to write a simple calling program (a utility to do this is included). It includes a huge set of table manipulation functions (record addition, change, view, copy, and removal), table sorting, filtering, table lookups, and more.

Download (gz).

Setting up a new Wordpress blog

TDavid — Wed, 02 Nov 2005 17:52:29 +0000

This guide assumes you have already downloaded and unzipped/untarred the most current Wordpress version. These instructions do not cover the multi-user WP version.

Steps for setting up a new Wordpress (WP) blog:

1. Database created? Create a MySQL database for the domain.

Note: If you have more than one WP blog installed in the same database then open up wp-config.php and change the ‘wp_’ to something else like ‘wp2_’ so that you can run multiple wordpress blogs in the same database.

2. Edit wp-config.php with the database information. Create a subdirectory in the WP version locally so you can backup the wp-config locally there.
3. FTP all WP files to the target domain, including the customized wp-config.php file in step #2.
4. Run the install file from your browser. Default install location is:

domain.com/wp-admin/install.php

5. Record the admin username and password somewhere safe.
6. Delete the install files: install.php, install-helper.php
7. Create a primary user: Users -> Authors & Users -> Add New User
8. Promote this user to Level 9 (which is one level beneath the Admin level of 10).
9. Add whatever plugins you want to use. Here’s some you might try:

bad behavior - shut down the spambots
codesnippet - allows you to include code snippets inside posts
dashboard options - add PHP code snippets, RSS feeds and more to your dashboard
follow - removes the rel=nofollow links from comments
wp-cache 2.0 - cache pages to speed up loading
page navigation - adds page spanning 1,2,3… to WP pages
WP-Dash - replace the default admin area

10. Clean up the default Links area, adding/removing any default links.
11. Delete the test post and make a first test placeholder post. Something like “Hello World” but by this new user.
12. Choose a template or design your own. Starting with the default template might be helpful. There are detailed instructions at the WP codex for how to make custom WP templates.
13. Start posting!

This post will be updated over time as I’m using this for my own reference too, so might want to bookmark this one.

MySQL 5.0 production version now available, includes subqueries

TDavid — Tue, 25 Oct 2005 02:46:58 +0000

MySQL 5.0 is now ready for use on production servers touting the following features: stored procedures and SQL functions, triggers, views, cursors, information schema, XA distributed transactions, SQL mode, new federated and archive storage engines, new migration toolkit, instance manager, updated connectors, visual tools and more.

Complete list of changes in 5.0.x production.

The functionality I’m excited about is subqueries: “MySQL 5.0 supports all subquery forms and operations that the SQL standard requires, as well as a few features that are MySQL-specific.”

I’m going to install this on a machine and start checking it out.

ARSC v3.0.2 RC 2 free chat

TDavid — Mon, 10 Oct 2005 15:39:34 +0000

Looking to add chat to your server? Don’t want to mess with java and IRC? Want to try a PHP/MySQL solution? ARSC could be for you.

From the 4-step installation from INSTALL docs:

- Create a MySQL database
- Provide the hostname, username, password, and database
name to allow ARSC to connect to your MySQL Server
- Copy the ARSC files onto the webserver
- Open the install script url in the webbrowser

We have been looking to do some kind of chat for Webmaster Cookbook, so I just conducted a quick installation there to see how long the base installation actually took.

Started 8:02am. End: 8:15am. 13 minutes which included creating the database and user/pass in PHPMyAdmin and FTPing the files.

Notes
- don’t forget to delete the install subdirectory
- customize the outside and inside pages using the layout option in the admin area

Query results within last X days

TDavid — Wed, 05 Oct 2005 14:10:05 +0000

Sometimes it is necessary to query data from the last 7 days. Here’s how to create a dynamic query inside a script using PHP / MySQL to return a list of users who last visited within X number of days (7 by default):

$now = time(); // this is the current UNIX timestamp for the server
$days = 7; // change to number of days
$days_ago = date(“Y-m-d H:i:s”, ($now - (86400 * $days));
$query = “SELECT username FROM users WHERE lastvisited > ‘$days_ago’”;
$result = @mysql_query($query,$mysql_link);
if(@mysql_num_rows($result)) {
while($row = mysql_fetch_row($result)) {
print “$row[0]
”;
}
}
?>

Notes:
- $mysql_link contains the MySQL database connection link.
- 86400 is the number of seconds in a day: 60 seconds x 60 minutes x 24 hours = 86,400

Changing databases inside code

TDavid — Fri, 30 Sep 2005 00:21:57 +0000

To change MySQL databases within code use the mysql_select_db() function like this:

mysql_select_db(‘db_2′, $mysql_link);
$query = “SELECT username from user where userid = ‘$user_id’”;
$result = mysql_query($query,$mysql_link);
if(mysql_num_rows($result)) {
$row = mysql_fetch_row($result);
$username = $row[0];
}
mysql_select_db(‘db_1′, $mysql_link);
?>

This code checks db_2 for the username by $user_id.

How to join an ID list using IN MySQL function

TDavid — Thu, 15 Sep 2005 02:12:21 +0000

How to create a query list of ID numbers using join from an $array and put into a string that can be used in a MySQL query:

$id_numbers = array(1,6,14,32,84,27,49,77);
$complist = join(”,”, $id_numbers);
$query = “SELECT id from tablename WHERE id IN($complist)”;