Can’t Connect to MySQL Server Remotely on Ubuntu


MySQL by default will not allow incoming remote connections for security reasons. In this article we will edit the MySQL config file mysqld.cnf to allow remote connections.

Testing a Remote MySQL Connection

To test a remote MySQL connection in Linux terminal, simply replace username and hostname_or_ip with your own.

mysql -u username -h hostname_or_ip -p

Or via Command Line in Windows:

telnet 3306

If you are getting an error when trying to connect to your remote MySQL server

ERROR 2003 (HY000): Can't connect to MySQL server on '' (111)

or in Windows Telnet

Connecting To not open connection to the host, on port 3306: Connect failed

1. Edit MySQL config

You may need to comment out bind-address in the MySQL config file mysqld.cnf.

Open mysqld.cnf with nano editor.

sudo nano /etc/mysql/mysql.conf.d/mysqld.cnf

Press CTRL + W and search for bind-address

# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address =

The above line is telling MySQL to only accept local connections. Comment out this line by adding # before it so it looks like:

# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
# bind-address =

Restart the MySQL service for changes to take effect.

sudo service mysql restart

Now try to connect to MySQL remotely again.

2. Check Firewall

If you still can’t connect, check if there is a firewall configured on your server. The most common firewall for Ubuntu server is ufw.

Check if ufw is enabled:

sudo ufw status

If it’s enabled, you should see some rules:

To                         Action      From
--                         ------      ----
OpenSSH                    ALLOW       Anywhere
Apache Full                ALLOW       Anywhere
OpenSSH (v6)               ALLOW       Anywhere (v6)
Apache Full (v6)           ALLOW       Anywhere (v6)

If MySQL is not listed, add a rule for it.

sudo ufw allow mysql

There should be a rule for MySQL:

To                         Action      From
--                         ------      ----
OpenSSH                    ALLOW       Anywhere
Apache Full                ALLOW       Anywhere
3306                       ALLOW       Anywhere
OpenSSH (v6)               ALLOW       Anywhere (v6)
Apache Full (v6)           ALLOW       Anywhere (v6)
3306 (v6)                  ALLOW       Anywhere (v6)

Restart the ufw service:

sudo service ufw restart

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Faceted navigation in PHP and MySQL


In this tutorial we are going to build a simple PHP/MySQL faceted navigation from scratch. In case you don’t know what faceted navigation is (or faceted search, layered navigation), it’s the nice filtering mechanism you see on most e-commerce sites in some form or another next to the product listing (see image).

Magento faceted navigation example

With each newly selected filter the resultset is narrowed down accordingly which allows user to quickly find the items (products, classifieds, articles, etc.) that meet their criteria. This search mechanism is most useful when a dataset needs to be filtered based onmultiple properties.

Unfortunately MySQL does not support faceted search out-of-the-box. There are dedicated external search applications such as SOLR or ElasticSearch which index the facets automatically for filtering. However not everyone has the knowledge or resources required to run such an application. Luckily we can achieve similar results while maintaining good performance using MySQL and PHP by setting up an index table and making some clever table joins.

The example data

You can download an SQL export of all the example data here.
Let me first introduce the dataset we’re going to work our magic on for this example:

table: products
| id | name                  | type     | brand           | colour |
|  1 | Black Jacket by Acme  | jacket   | Acme Apparel    | black  |
|  2 | Blue Jacket by Acme   | jacket   | Acme Apparel    | blue   |
|  3 | Blue Jacket by FF     | jacket   | Fictive Fashion | blue   |
|  4 | Orange Trousers by FF | trousers | Fictive Fashion | orange |

The faceted navigation in this example without any of the filters selected will look something like this:

Jacket (3)
Trousers (1)
Acme Apparel (2)
Fictive Fashion (2)
Black (1)
Blue (2)
Orange (1)

The user can filter the product overview simply clicking on the filter links which makes it a form of navigation to the user (hence the term faceted navigation).

Note the item counts next to each facet value, these will be updated to reflect the current resultset whenever a filter is added or removed.


Faceted navigation index tables

To perform the faceted search in MySQL we need to create two extra tables. One table contains a list of the product facets and the other contains facts about the products.

table: product_facets
| id | name   |
|  1 | type   |
|  2 | brand  |
|  3 | colour |

table: product_facts
| product_id | facet_id | facet_name | value           |
|          1 |        1 | type       | jacket          |
|          1 |        2 | brand      | Acme Apparel    |
|          1 |        3 | colour     | black           |
|          2 |        1 | type       | jacket          |
|          2 |        2 | brand      | Acme Apparel    |
|          2 |        3 | colour     | blue            |
|          3 |        1 | type       | jacket          |
|          3 |        2 | brand      | Fictive Fashion |
|          3 |        3 | colour     | blue            |
|          4 |        1 | type       | trousers        |
|          4 |        2 | brand      | Fictive Fashion |
|          4 |        3 | colour     | orange          |

We used the following PHP function to automatically populate the facts table with data. You’ll need to make sure the product_facts table gets updated for each CRUD operation on the original dataset.

 * Populates the product_facts table with data from the products table
 * @param object $mysql_connection the mysql connection object
function populate_product_facts($mysql_connection) {
  //empty product_facts table
  mysqli_query($mysql_connection"TRUNCATE product_facts");  
  //fetch all product data
  $result = mysqli_query($mysql_connection"SELECT * FROM products");
  //loop through resultset rows
  while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {
    $facet_id = 1;
    //loop through table columns
    foreach ($row as $key => $value) {
      //create facts for all product fields except 'id' and 'name'
      if ($key != "id" && $key != "name") {
        $sql "INSERT INTO product_facts VALUES (" $row['id'] . ",$facet_id,'$key','$value');";
        echo "Added fact: (".$row['id'].", $facet_id, $key, $value) <br/>";

Now that we have set up all the required tables we will look at how to query the tables in the next section.

Querying the data

Let’s say a user just opened the product browse page and hasn’t selected any filters yet. To retrieve the product data we can simply execute the query:

SELECT FROM products;

This will return a list of all products.

To construct the faceted navigation HTML we need to query the product_facts table.

SELECT pf.facet_name, pf.value, count(*) AS c
FROM product_facts pf
GROUP BY pf.facet_id, pf.value;

Which produces the following result:

| facet_name | value           | c |
| type       | jacket          | 3 |
| type       | trousers        | 1 |
| brand      | Acme Apparel    | 2 |
| brand      | Fictive Fashion | 2 |
| colour     | black           | 1 |
| colour     | blue            | 2 |
| colour     | orange          | 1 |

As you can see this contains all the data required to output the faceted navigation (including counts).

Now let’s say that a user selects the colour blue so that only blue products are shown. This changes the product query to:

SELECT FROM products
WHERE colour='blue';

Similarly the query to retrieve the facet data becomes:

SELECT pf.facet_name, pf.value, count(*) AS c
FROM product_facts pf
JOIN products p ON pf.product_id =
WHERE p.colour='blue'
GROUP BY pf.facet_id, pf.value;

Which results in:

| facet_name | value           | c |
| type       | jacket          | 2 |
| brand      | Acme Apparel    | 1 |
| brand      | Fictive Fashion | 1 |
| colour     | blue            | 2 |

We can add an ORDER BY statement to sort the list of filters alphabetically:

SELECT pf.facet_name, pf.value, count(*) AS c
FROM product_facts pf
JOIN products p ON pf.product_id =
GROUP BY pf.facet_id, pf.value
ORDER BY pf.facet_name, pf.value;

When the user selects multiple filters we simply add multiple conditions in the WHERE clause based on the selected filters.

In the next post I’ll explain how to create the interactive faceted navigation HTML interface based on the work we’ve done so far.

If you have any questions please leave a comment below!

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Install Apache + PHP + MySQL in Ubunut

We can Install Apache, PHP and MySQL in Ubuntu 3 types as bellow:

  1. When install Ubuntu Screen, please select ( [x] LAMP SERVER)
  2. Go to terminal :
    sudo apt-get install lamp-server^
  3. Install all application one by one as:


1 Preliminary Note

In this tutorial I use the hostname with the IP address These settings might differ for you, so you have to replace them where appropriate.

I’m running all the steps in this tutorial with root privileges, so make sure you’re logged in as root:

sudo su


2 Installing MySQL 5

First we install MySQL 5 like this:

apt-get install mysql-server mysql-client

You will be asked to provide a password for the MySQL root user – this password is valid for the user root@localhost as well as, so we don’t have to specify a MySQL root password manually later on:

New password for the MySQL “root” user: <– yourrootsqlpassword
Repeat password for the MySQL “root” user: <– yourrootsqlpassword


3 Installing Apache2

Apache2 is available as an Ubuntu package, therefore we can install it like this:

apt-get install apache2

Now direct your browser to, and you should see the Apache2 placeholder page (It works!):

Click to enlarge


Apache’s default document root is /var/www on Ubuntu, and the configuration file is /etc/apache2/apache2.conf. Additional configurations are stored in subdirectories of the /etc/apache2 directory such as /etc/apache2/mods-enabled (for Apache modules), /etc/apache2/sites-enabled (for virtual hosts), and/etc/apache2/conf.d.


4 Installing PHP5

We can install PHP5 and the Apache PHP5 module as follows:

apt-get install php5 libapache2-mod-php5

We must restart Apache afterwards:

/etc/init.d/apache2 restart


5 Testing PHP5 / Getting Details About Your PHP5 Installation

The document root of the default web site is /var/www. We will now create a small PHP file (info.php) in that directory and call it in a browser. The file will display lots of useful details about our PHP installation, such as the installed PHP version.

vi /var/www/info.php


Now we call that file in a browser (e.g.

Click to enlarge


As you see, PHP5 is working, and it’s working through the Apache 2.0 Handler, as shown in the Server API line. If you scroll further down, you will see all modules that are already enabled in PHP5. MySQL is not listed there which means we don’t have MySQL support in PHP5 yet.


6 Getting MySQL Support In PHP5

To get MySQL support in PHP, we can install the php5-mysql package. It’s a good idea to install some other PHP5 modules as well as you might need them for your applications. You can search for available PHP5 modules like this:

apt-cache search php5

Pick the ones you need and install them like this:

apt-get install php5-mysql php5-curl php5-gd php5-intl php-pear php5-imagick php5-imap php5-mcrypt php5-memcache php5-ming php5-ps php5-pspell php5-recode php5-snmp php5-sqlite php5-tidy php5-xmlrpc php5-xsl

Now restart Apache2:

/etc/init.d/apache2 restart

Xcache is a free and open PHP opcode cacher for caching and optimizing PHP intermediate code. It’s similar to other PHP opcode cachers, such as eAccelerator and APC. It is strongly recommended to have one of these installed to speed up your PHP page.

Xcache can be installed as follows:

apt-get install php5-xcache

Now restart Apache:

/etc/init.d/apache2 restart

Now reload in your browser and scroll down to the modules section again. You should now find lots of new modules there, including the MySQL module:

Click to enlarge



7 phpMyAdmin

phpMyAdmin is a web interface through which you can manage your MySQL databases. It’s a good idea to install it:

apt-get install phpmyadmin

You will see the following questions:

Web server to reconfigure automatically: <– apache2
Configure database for phpmyadmin with dbconfig-common? <– No

Afterwards, you can access phpMyAdmin under

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MAMP: ERROR 2002 (HY000): Can’t connect to local MySQL server through socket ‘/tmp/mysql.sock’ (2)

I instaled MAMP and it worked great. However, when I tried to access mysql from the shell I was getting

$ mysql -u root -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

However, using a full path to MAMP binary worked.
$ /Applications/MAMP/Library/bin/mysql -u root -p

MAMP’s mysql works with another socket file which is located at /Applications/MAMP/tmp/mysql/mysql.sock

All you have to do is:
sudo ln -s /Applications/MAMP/tmp/mysql/mysql.sock /tmp/mysql.sock

UPDATE: As it turns out the above soft link gets erased by the system, so you need to run the command every once in a while. At one point it got too frustrating so I figured out a permanent way to take care of this problem. Open /etc/my.cnf and add/edit these lines:


Instead of telling MAMP which socket file to use, you are instructing the mysql client to use MAMP’s default socket.

Let me know if this works for you.


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Recover MySQL root Password

You can recover MySQL database server password with following five easy steps.

Step # 1: Stop the MySQL server process.

Step # 2: Start the MySQL (mysqld) server/daemon process with the –skip-grant-tables option so that it will not prompt for password.

Step # 3: Connect to mysql server as the root user.

Step # 4: Setup new mysql root account password.

Step # 5: Exit and restart the MySQL server.

Here are commands you need to type for each step (login as the root user):

Step # 1 : Stop mysql service

# /etc/init.d/mysql stop

Stopping MySQL database server: mysqld.

Step # 2: Start to MySQL server w/o password:

# mysqld_safe --skip-grant-tables &

[1] 5988
Starting mysqld daemon with databases from /var/lib/mysql
mysqld_safe[6025]: started

Step # 3: Connect to mysql server using mysql client:

# mysql -u root

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 4.1.15-Debian_1-log

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.


Step # 4: Setup new MySQL root user password

mysql> use mysql;
mysql> update user set password=PASSWORD("NEW-ROOT-PASSWORD") where User='root';
mysql> flush privileges;
mysql> quit

Step # 5: Stop MySQL Server:

# /etc/init.d/mysql stop

Stopping MySQL database server: mysqld
STOPPING server from pid file /var/run/mysqld/
mysqld_safe[6186]: ended

[1]+  Done                    mysqld_safe --skip-grant-tables

Step # 6: Start MySQL server and test it

# /etc/init.d/mysql start
# mysql -u root -p

MySQL Case-Sensitive Query

MySQL queries are not case-sensitive by default. Following is a simple query that is looking for ‘value’. However it will return ‘VALUE’, ‘value’, VaLuE’, etc…

SELECT *  FROM `table` WHERE `column` = ‘value’

The good news is that if you need to make a case-sensitive query, it is very easy to do:

SELECT *  FROM `table` WHERE BINARY `column` = ‘value’

Data truncation: Incorrect datetime value in MySQL

Message Error in MySQL:
“Data truncation: Incorrect datetime value: ‘1969-12-31 16:00:00’ for column ‘LAST_LOGIN’ at row 1”


Now, open the my.ini file located at c:program files/MySQL/MySQL
Server X.x/my.ini.
Add a # at the begining of the line: sql-mode=”STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION”

sql_mode=” on the next line and save the file.
restart mysql

Select data that is not match data in another table in MySQL

We have mock up data in both table as below:

ID Name
1 Mr. A
2 Ms. B
3 Mrs. C


ID Table1ID Name
1 3 ABC Beer
2 1 Tiger Beer

And we want to select data in table1 that is not avaiable in table2, so when you want to do as I said.

You should use:

SELECT table1.*

FORM table1 LEFT JOIN table2 ON table1.ID = table2.Table1ID

WHERE table2.Table1ID is null



ID Name
2 Ms. B