Question

PHP

Review

For the Programming part:

1. How to connect to Database: connecting string, query string mysqli_connect(), mysqli_query()

2. mysqli_fatch_array() - records returned, with while loop

3. form and name of variables that can be retrieved in php file.=> $_POST, $_GET

4. all the variables that a php file can access: _GET, _POST, SEVER, ... global variables with respect to the get and post methods in the form.

5. Where (Which directory) you store the database connecting information? parallel to htdocs folder why? no one can access except the admin

6. difference between GET and POST methods

7. Include multiple files: include, include_once, require, require_once

8. what is a sticky form?

Answer 1

I have answered the first 4 subparts as there are a total of 8 parts of the question.

1. How to connect to Database: connecting string, query string mysqli_connect(), mysqli_query()

<?php
$conn = mysqli_connect("localhost","username","password","name_of_database");
if(mysqli_connect_error())
{
echo "Error in connection";
}
mysqli_query($conn,"SQL_query"),
// mysqli_query($conn,"SELECT * FROM employee")
mysqli_close($conn);
?>

2. mysqli_fatch_array() - records returned, with while loop

<?php
$conn = mysqli_connect("localhost","username","password","name_of_database");
if(mysqli_connect_error())
{
echo "Error in connection";
}
$data = mysqli_query($conn,"SELECT * from table_name");
while($rw = mysqli_fetch_assoc($data));
{
$col_1 = $rw['col_1'];
$col_2 = $rw['col_2'];
$col_n = $rw['col_n'];
echo $col_1 +" "+$col_2+" "+$col_n+<br>;
}

?>

3. form and name of variables that can be retrieved in PHP file.=> $_POST, $_GET

$_POST: Post method is used to send data to the database. It is more secure and has no limitations like the character limit or the file type that has to be stored in the database. In the case of the post method, the data is stored in an associative array and can information can be accessed using the same.

$_GET: It is used to retrieve the data from the database and is less secure as compared to post as the data gets displayed in the form of a string on the server log. It is limited to only 1024 characters and cannot be used to send images.

;" src= "https://media.HomeworkLibcdn.com/media/762/762cec2b-93c1-4c6a-a09c-2d1635e42776/php72QIAu.png" />

4. all the variables that a PHP file can access: _GET, _POST, SEVER, ... global variables with respect to the get and post methods in the form.

Global variables of PHP are :

• $ GLOBALS: It is used to access global variables from anywhere in the PHP file. In PHP these global variables are stored in the form of an array: $GLOBALS[]
• $ _SERVER: It stores information about header, path and location of script. Eg. $_SERVER['SERVER_NAME] : Returns the name of host server.
• $ _REQUEST: It is used to collect data after an HTML form has been submitted. Eg. $var = $_REQUEST['name'];
• $ _FILES: Used to upload files like images, pdf etc in PHP.
• $_COOKIE: Cookies help in reducing latency by storing the basic information about the user such that if the same page is visited again by the user the basic information is automatically filled.
• $ _SESSION: It is a method of passing variables from one page to another. It can be done by creating a session and storing the variables in the session and then it can be accessed anywhere in the server.