SQL | Foreign Key A foreign key is a key used to link two tables.    A Primary key of a table is used as a foreign key for the other table. The primary key …

MySQL | Find last insert id in the table By using the MySQL function mysqli_insert_id() we can retrieve the last inserted id in the database table.   <?php $con = mysqli_connect("localhost","user_name","user_password","db_name"); if (mysqli_connect_errno()) { echo …

By using following query we can find out the nth largest salary from employees table. SELECT salary FROM `employees` ORDER BY salary DESC LIMIT 1 OFFSET n-1 In the above query n is replaced by …

PHP | Access specifiers An access specifier is a code element that is used to determine which part of the program is allowed to access a particular variable or other information.   There are three …

MySQL | Repair Table REPAIR command is used for repair a MySQL table REPAIR TABLE users We can also specify Quick and Extended after the table name REPAIR TABLE users QUICK If we specify Quick then MySQL will …

PHP | Redirect PHP header() function is used to redirect a page to another page. It supplies raw HTTP headers to the browser and redirects it to another location. The redirection script should be at …

PHP | magic function In PHP all functions start with __ names are magical functions. Magical functions always live in a PHP class. The definition of the magical function is defined by the programmer itself. …

SQL Update statement The UPDATE statement is used to update the records of an existing table in a database. We can update single as well as multiple columns using SQL update statement. The basic syntax …

List  List is a language construct and is similar to an array. It is used to assign a list of variables in one operation. If you are using PHP 5, then the list values start …

Cross-site scripting (XSS) Cross-site scripting (XSS) is a type of computer security vulnerability typically found in web applications. XSS enables attackers to inject client-side script into web pages viewed by other users. A cross-site scripting …

PHP | How to avoid errors in PHP? We can use PHP inbuilt function error_reporting(0) to avoid all errors in PHP file. <?php error_reporting(0); ?>  

PHP | Check data type in php | gettype() | var_dump() By using gettype() function we can check the data type of a variable. we can also use var_dump() function for the same.   gettype() <?php echo …

Googlebot | What is a robots.txt file? A robots.txt is a simple text file that can be created by a notepad editor. This file is used for search engines, which provide instructions to search engines on how …

OPTIMIZE command is use for optimize a table. OPTIMIZE TABLE `users`  

PHP |  date() function By using the PHP date() function we can find the current date and time. <?php echo date(“d-m-Y”); //This will print today date. echo date (“d-m-Y h:i:s”) // This will print today’s date …