Mysql query not executing in PHP | mysql query not working in php

                  Mysql query not executing in PHP

Reasons why Mysql query is not executing in PHP 

⦁ you might missed establishing connection with database⦁ you might trying to execute query before  establishing connection with database⦁ your database connection query might be worng⦁ your query might be wrong ⦁ Mysql server might be not running

To establish connection with database query should be like this :

    //Database Connection Var    $db = mysqli_connect("localhost", 'user', 'password', 'database_name');

you might trying to execute query before  establishing connection with database

first of all create connection with database  and get connection variable before try to execute any query.

your database connection query might be worng

 if you are login as 'root'  user then  //Database Connection Var     $db = mysqli_connect("localhost", 'root', ' ', 'database_name');

your query might be wrong 

check your query   eg: if query is to insert data then  prepare your query as:$sql = "INSERT INTO table (`username`, `email`, `address`, `mobile no`) VAUES('" .$user."', '" .$email."', '" .$address."', '" .$mob"')";

How are you executing query

$query = mysql_query($sql) or trigger_error("Queryfailed : ".mysql_error()); - mysql_query($sql) should bemysql_query(Database_Connection_Var,$sql) ;

You might be missing database connection variable missed.

mysql_query($db,$sql) ;

Mysql server might be not running

• check mysql server whether it is running or not
• if you are using WAMP server then check 

• 

  MySQL is not running
  

• 

  MySQL is running
  

   if Mysql is not running then WAMP server will not be green 

         if it is not green the restart WAMP

• if still it is not working then change port number of mysql server
• if all above methods not work then one way to reinstall your wamp server 
•   but if you reinstall it then you might loss your database