Add doc for setting up a MySQL database Terminal and creating database connection with PHP

[ghost]

Author: Graham A. Sutton

***** This is the original way before Cloud 9 added phpMyAdmin for setting up a MySQL database in Cloud 9 and forming a simple connection via PHP. This is for those who do not want to bother with phpMyAdmin or prefer creating and managing their databases in Terminal. *****

Original write-up was posted as answer to a Stack Overflow question which can be found here: http://stackoverflow.com/questions/19531822/php-connect-to-mysql-db-in-cloud-9/26986286#26986286

Credit to Brady Dowling for suggesting I create a pull request on this matter.

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_If you want the quick rundown, just scroll to _Step 3* and read on from there. If you're a complete beginner, keep reading as I'll walk you through it in detail.*

Couple things to mention:

• You will have to setup a database via a Terminal in Cloud 9. I had no experience prior doing it in a Terminal before, but it's very simple to learn.
• You can not use mysql functions, you have to use mysqli, since mysql functions are deprecated and Cloud 9 will not run them.

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Step 1: Setup MySQL on Cloud 9 (in Terminal)

In your project, open up a New Terminal (click the plus-sign tab above the text editor space, select "New Terminal"). In the terminal, type mysql-ctl start and hit Enter. MySQL will start up in the back, but you won't get any response back in the terminal.

Next, type mysql-ctl cli and hit Enter. You should see some text that starts off as Welcome to the MySQL monitor.... Congrats, you've setup MySQL on your Cloud 9 project.

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Step 2: Create a test database (in Terminal)

You can actually go ahead and create your official database if you like, but for this sake I'll just make a database that holds a table that holds an ID and a username. So here's the steps to setting up a database and a table. If you've used MySQL and databases before, then this should be cake, but I'll explain it in detail for those who might not fully understand MySQL .

1. Type SHOW DATABASES; and hit Enter. This will show a list of current databases within your project. You can enter this any time you want to see a list of your databases on the current project.
2. Type in CREATE DATABASE sample_db; and hit Enter. You should get a Query OK, 1 Row affected. which means the query was successful. You can name the database whatever you like, but for this little walk-through, I named it sample_db.
3. Type in USE sample_db; and hit Enter. This selects sample_db from the list of databases.
4. Type in CREATE TABLE users (id INT(11), username VARCHAR(20));, and hit Enter. This creates a table named users with two columns: id and username. The number in parentheses represents the character limit the column will store in the database. In this case for example, username won't hold a string longer than 20 characters in length.
5. Type in INSERT INTO users (id, username) VALUES (1, "graham12");, and hit Enter. This will add the id of 1 and a username graham12 in the table. Since the id column is an INT, we do not put quotes around it.
6. Type in SELECT * FROM users;, and hit Enter. This will show everything that is in the users table. The only entry in there should be what we inserted from the last step we just did.

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Step 3: Get the credentials you'll need to connect to the database from PHP. (in Terminal)

Now we have some data in our table that we can test our mysqli connection with. But first, we have to get the credentials we will need to connect to the database in PHP. In Cloud 9, we will need 5 credentials to connect:

1. Host name
2. Username
3. Password
4. Database name
5. Port #

Username, password, database name, and port #, are practically already known to you by now. I'll explain:

1. Host name - Type in SHOW VARIABLES WHERE Variable_name = 'hostname';, and hit Enter. You'll get a table that has 2 columns: Variable_name and Value. In the Value column you should see something like yourUsername-yourProjectName-XXXXXXX, where the X's are a 7 digit number. Write this number down or save it some where. This is your host name. (If you're getting the quick rundown on this walkthrough, just start a new terminal and start up your mysql and select the database you want to use, then type in SHOW VARIABLES WHERE Variable_name = 'hostname';. Re-read this step from the beginning if you're confused.)
2. Username - Your username that you use to log in to Cloud 9.
3. Password - There is _NO_ password for your database in Cloud 9.
4. Database name - This would be sample_db or whatever you named your database;
5. Port # - is 3306. In Cloud 9, all of your projects are wired to 3306. This is a universal constant of Cloud 9. It will not be anything else. Write this as you would an integer, not as a string. mysqli_connect() will interpret the port # as a long data type.

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Last Step: Connect to the database with PHP! (using PHP)

Open up a PHP file and name it whatever you like.

I'll pretend that my host name is graham12-sample_db-1234567 for this example and that this is what my data looks like:

• Host name: "graham12-sample_db-1234567"
• Username: "graham12"
• Password: ""
• Database name: "sample_db"
• Port #: 3306

So in PHP, insert your credentials accordingly:

<?php

    //Connect to the database
    $host = "grahamsutt12-sample_db-1234567";   //See Step 3 about how to get host name
    $user = "grahamsutt12";                     //Your Cloud 9 username
    $pass = "";                                 //Remember, there is NO password!
    $db = "sample_db";                          //Your database name you want to connect to
    $port = 3306;                               //The port #. It is always 3306

    $connection = mysqli_connect($host, $user, $pass, $db, $port)or die(mysql_error());



    //And now to perform a simple query to make sure it's working
    $query = "SELECT * FROM users";
    $result = mysqli_query($connection, $query);

    while ($row = mysqli_fetch_assoc($result)) {
        echo "The ID is: " . $row['id'] . " and the Username is: " . $row['username'];
    }

?>

If you get a result and no error then you have successfully setup a database and formed a connection to it with PHP in Cloud 9. You should now be able to make all the queries you can normally make.

Note: I demonstrated the last part without using parameterized queries for the sake of being simple. You should always use parameterized queries when working with real web applications. You can get more info on that here: MySQLi Prepared Statements.