Development Blog by Professionals
MySQL
MySQL errors into PHP?
Apr 19th
Here are some examples of how to utilize mysql_error ()
mysql_connect("your.hostaddress.com",
"username", "password") or die(mysql_error()) This will return an error if there is a problem connecting to your MySQL database
$value = mysql_query($your_query)
or die("A MySQL error has occurred.<br />Your Query: " .
$your_query . "<br /> Error:
(" . mysql_errno() . ") " . mysql_error())When you encounter an error, this will return your custom message (A MySQL error has occurred.<br />) followed by a line number, and the actual
thanks http://php.about.com/od/phpwithmysql/f/mysql_error.htm
Quotes in mysql queries – security issue
Mar 10th
Remember to check numeric data as well. If an application generates a query such as SELECT * FROM table WHERE ID=234 when a user enters the value 234,the user can enter the value 234 OR 1=1 to cause the application to generate the query SELECT * FROM table WHERE ID=234 OR 1=1.As a result, the server retrieves every row in the table. This exposes every row and causes excessive server load. The simplest way to protect from this type of attack is to use single quotes around the numeric constants: SELECT * FROM table WHERE ID='234'. If the user enters extra information, it all becomes part of the string. In a numeric context, MySQL automatically converts this string to a number and strips any trailing nonnumeric characters from it. It means that if the user enters 234myname the value remains 234. Another option is to do a check before the mysql query if the value is numeric.
Source http://dev.mysql.com/doc/refman/5.0/en/security-guidelines.html
Mysql Select within Select (sel into sel)
Jan 14th
SELECT clients.id, (SELECT Count(clients_job.id) FROM clients_job WHERE clients_job.client_id = clients.id ) AS JobCounter FROM clients ORDER BY EPONIMIA ASC
PHP mysqli::set_charset
Jan 12th
In connection file add the following lines
$mysqli = new mysqli($hostname_###,$username_###,$password_###,$database_###);
$mysqli->query(“SET NAMES ‘utf8′”);
Mysqli Tutorial
Jan 8th
Moving from a procedural system to object-oriented can be a daunting task. One feature to assist you is the MySQLi class, which allows for an object-oriented approach to database manipulation. This tutorial gives insight into the structure and basic usage of the MySQLi class. If PDO isn’t an option for you, then try MySQLi! More >
ORDER BY using specific order from IN
Oct 19th
You can use FIND_IN_SET to do that:
SELECT * FROM tablename WHERE id IN (1,10,8,5) ORDER BY FIND_IN_SET(id, ’1,10,8,5′)
Php, MySql, .htaccess: friendly urls
Jul 26th
Php, MySql, .htaccess: friendly urls
There are a lot of tutorials that show how to change an address like:
- www.mysite.com/products.php?product_id=1234
into others like:
- www.mysite.com/products/1234
- www.mysite.com/products/1234.html
In this article I’d like to go one step forward and to create something like:
- www.mysite.com/easy-to-remember-product-name
- www.mysite.com/easy-to-remember-product-name.html More >
mysql console backup restore
Jul 21st
Question: How to backup the whole database?
Answer: Just omit the “table_name” argument. For example, mysqldump -u root -pwordpress > D:\wordpress.sql
Question: How to backup all the databases in MySQL?
USE –force to continue on errors
Answer: Use “–all-databases”. For example, mysqldump -u root -p –all-databases > D:\db.sql
linux mysqldump -u admin -p –all-databases > db.sql
Restoring
Now let’s to restore it. Enter the following command in the command line window (or shell):
mysql -u root -p wordpress < D:\wordpress_posts.sql
This will restore the “wp_posts” table. You need to specify the database name. Here, it is “wordpress“. The following command restore the whole database:
mysql -u root -p wordpress < D:\wordpress.sql
If you want to restore all the databases (you used “–all-databases” argument to generate a backup file before), you don’t need to specify the database name.
mysql -u root -p < D:\db.sql
mysql: “not cleanly closed and upgrade needing tables” problem
Jun 25th
I have used mysql server on my laptop with gutsy on xfs file system. I have tested on hardy version and have same output as following
Quote:
sudo /etc/init.d/mysql start
* Starting MySQL database server mysqld [ OK ]
* Checking for corrupt, not cleanly closed and upgrade needing tables.
I google and couldn’t find a clean solution. I have already do
Quote:
myisamchk *.MYI
myisamchk –recover *.MYI
myisamchk –safe-recover *.MYI
But unfortunately problem still there. I need your help about why and how this can be solved. Thank a lot for your help.
