1. The mysqli_affected_rows() function returns the number of affected rows in the previous SELECT, INSERT, UPDATE, REPLACE,or DELETE query.
2. Syntax
mysqli_affected_rows( connection);

1.The mysqli_connect_error() function returns the error description from the last connection error, if any.
2.Syntax
mysqli_connect_error( );

1. The mysqli_fetch_assoc() function fetches a result row as an associative array .
2. Syntax
mysqIi_fetch_assoc(result);

1. A Web database is a database application designed to be managed and accessed through the Internet.
2. In other words, the light databases that support the web applications are also known as Web Databases

Database Connections: Accessing MySQL Database, connect to Database Server machine via PHP scripting language using Mysqli_connect() Function.
Syntax:
mysqli_connect("Server Name","User Name","Password","DB Name");
This function requires four parameters to connect to database server. Database Server name, Database username, password and Database Name.

Syntax:
mysqli_connect("Server Name","User Name","password","DB Name");
Example:

mysqli_affected rows( )	mysqli_fetch_assoc( )
It returns the number of affected rows in the prearvious SELECT, INSERT  UPDATE, REPLACE, or DELETE query.	It fetches a result rowas an associative aray
Return value: An integer >0 indicates the  number of rows affected (0 indicates that no records were affected. '-1' indicates that the query returned an error).	Returns an associative array of strings representing the fetched row. NULL if there are no more rows in result set.
Syntax: mysqli_affected_rows (connection);	Syntax: mysqli fetch_as-soc(result);

In PHP Scripting language many functions are available for MySQL Database connectivity and executing SQL queries. MySQLi is extension in PHP Scripting language which gives access to the MySQL database. MySQLi extension was introduced version 5.0.0.

The MySQLi extension contains the following important functions which are related to MySQL database connectivity and management.
i) Mysqli_connect() Function
ii) Mysqli_close() Function
iii) Mysqli_query() Function

Performing Queries: The main goal of MySQL and PHP connectivity is to retrieve and manipulate the data from MySQL database server. The SQL query statements are help in PHP MySQL extension to achieve the objective of MySQL and PHP connection. “mysqli_query” is a function, that helps to execute the SQL query statements in PHP scripting language.
Syntax:
mysqli_query(“Connection Object”,“SQL Query”)
Example:
$con=mysqli_connect(“localhost”,“my_user”,“my_password”,“Student_DB”);
$sql=“SELECT student_name,student_age FROM student”;mysqli_query($con,$sql);