Simple PHP/MYSQL guide

[Jaan]

Well in this tutorial i will show how to do connect to database, how to add things and how to update things in your database.

1. Connecting

Syntax:

mysql_connect(servername,username,password);

Example:

PHP Code:

<?php

$connect = mysql_connect("localhost", "MyUsername", "MyPassword");
// If there's problem with connecting to database then this part will show this problem
if(!$connect){
die("Cannot connect to database ".mysql_error());
}

?>

2. Selecting a database

Syntax

mysql_select_db(database_name);

Example:

PHP Code:

<?php

$connect = mysql_connect("localhost", "MyUsername", "MyPassword");
if(!$connect){
die("Cannot connect to database ".mysql_error());
}

mysql_select_db("my_database");

?>

3. Creating a database

Syntax:

CREATE DATABASE databasename

Example:

PHP Code:

<?php

$connect = mysql_connect("localhost", "MyUsername", "MyPassword");
if(!$connect){
die("Cannot connect to database ".mysql_error());
}

if(mysql_query("CREATE DATABASE my_database"){
echo "Database created!";
}else{
echo "There was problem with creating a database: ".mysql_error();
}

?>

4. Inserting into database

Syntax:

INSERT INTO table_name VALUES (first_value, second_value, third_value)

or

INSERT INTO table_name (first_column, second_column, third_column) VALUES (first_value, second_value, third_value)

Example:

PHP Code:

<?php

$connect = mysql_connect("localhost", "MyUsername", "MyPassword");
if(!$connect){
die("Cannot connect to database ".mysql_error());
}

mysql_select_db("my_database");

mysql_query("INSERT INTO users (username, email, age) VALUES ('Jaan', 'jaan(at)et-resources.com', '15')");

?>

5. Selecting from database

Syntax:

SELECT column(s) FROM table_name

Example:

PHP Code:

<?php

$connect = mysql_connect("localhost", "MyUsername", "MyPassword");
if(!$connect){
die("Cannot connect to database ".mysql_error());
}

mysql_select_db("my_database");

// This * means ALL so.. select all from users
mysql_query("SELECT * FROM users");

?>

Example 2:

PHP Code:

<?php

$connect = mysql_connect("localhost", "MyUsername", "MyPassword");
if(!$connect){
die("Cannot connect to database ".mysql_error());
}

mysql_select_db("my_database");

mysql_query("SELECT email FROM users");

?>

Example 3:

PHP Code:

<?php

$connect = mysql_connect("localhost", "MyUsername", "MyPassword");
if(!$connect){
die("Cannot connect to database ".mysql_error());
}

mysql_select_db("my_database");

$select = mysql_query("SELECT * FROM users");

// This creates a loop which will repeat itself until there are no more rows to select from the database. We getting the field names and storing them in the $row variable. This makes it easier to echo each field. 
while($row = mysql_fetch_array($select)){

echo $row['username']. "<br>";
echo $row['age'];

}

?>

This is basic what you need to know. If you have more questions feel free to ask from me.

Have fun!