Delete Record From Datatbase Using MYSQL

 The SQL DELETE command is used to delete rows that are no longer required from the database tables. It deletes the whole row from the table. Delete command comes in handy to delete temporary or obsolete data from your database.The DELETE command can delete more than one row from a table in a single query. This proves to be advantages when removing large numbers of rows from a database table.

 Once a row has been deleted, it cannot be recovered. It is therefore strongly recommended to make database backups before deleting any data from the database. This can allow you to restore the database and view the data later on should it be required.

Syntax

The following code block has a generic SQL syntax of the DELETE command to delete data from a MySQL table.

DELETE FROM table_name [WHERE Clause]

• If the WHERE clause is not specified, then all the records will be deleted from the given MySQL table.
• You can specify any condition using the WHERE clause.
• You can delete records in a single table at a time.

The WHERE clause is very useful when you want to delete selected rows in a table.

Deleting Data from the Command Prompt

This will use the SQL DELETE command with the WHERE clause to delete selected data into the MySQL table – tutorials_tbl.

Example

The following example will delete a record from the tutorial_tbl whose tutorial_id is 3.

root@host# mysql -u root -p password;
Enter password:*******

mysql> use TUTORIALS;
Database changed

mysql> DELETE FROM tutorials_tbl WHERE tutorial_id=3;
Query OK, 1 row affected (0.23 sec)

mysql>

Deleting Data Using a PHP Script

You can use the SQL DELETE command with or without the WHERE CLAUSE into the PHP function – mysql_query(). This function will execute the SQL command in the same way as it is executed at the mysql> prompt.

Example

Try the following example to delete a record from the tutorial_tbl whose tutorial_id is 3.

<?php
   $dbhost = 'localhost';
   $dbuser = 'root';
   $dbpass = '';
   $conn = mysql_connect($dbhost, $dbuser, $dbpass);
   
   if(! $conn ) {
      die('Could not connect: ' . mysql_error());
   }

   $sql = 'DELETE FROM tutorials_tbl WHERE tutorial_id = 3';

   mysql_select_db('TUTORIALS');
   $retval = mysql_query( $sql, $conn );

   if(! $retval ) {
      die('Could not delete data: ' . mysql_error());
   }
   echo "Deleted data successfully\n";
   mysql_close($conn);
?>

Update Data With MYSQL

 There may be a requirement where the existing data in a MySQL table needs to be modified. You can do so by using the SQL UPDATE command. This will modify any field value of any MySQL table.

Syntax

The following code block has a generic SQL syntax of the UPDATE command to modify the data in the MySQL table −

UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value 

You can update one or more field altogether.

The WHERE clause is very useful when you want to update the selected rows in a table.

Updating Data Using a PHP Script

You can use the SQL UPDATE command with or without the WHERE CLAUSE into the PHP function – mysql_query(). This function will execute the SQL command in a similar way it is executed at the mysql> prompt.

Example

The following example to update the tutorial_title field for a record having tutorial_id as 3.

<?php
   $server = 'localhost';
   $username = 'root';
   $password = '';
   $conn = mysql_connect($dbhost, $dbuser, $dbpass);
   
   if(! $conn ) {
      die('Could not connect: ' . mysql_error());
   }

   $sql = 'UPDATE tutorials_tbl
      SET tutorial_title="Learning JAVA"
      WHERE tutorial_id=3';

   mysql_select_db('TUTORIALS');
   $retval = mysql_query( $sql, $conn );
   
   if(! $retval ) {
      die('Could not update data: ' . mysql_error());
   }
   echo "Updated data successfully\n";
   mysql_close($conn);
?>

What PHP is?

 

PHP stands for Hypertext Preprocessor. PHP is a powerful and widely-used open source server-side scripting language to write dynamically generated web pages. PHP scripts are executed on the server and the result is sent to the browser as plain HTML.

 PHP can be integrated with the number of popular databases, including MySQL, PostgreSQL, Oracle, Sybase, Informix, and Microsoft SQL Server.

PHP can be embedded within a normal HTML web pages. That means inside your HTML documents you'll have PHP statements like this:



Example:

<!DOCTYPE HTML>
<html>
<head>
    <title>PHP Application</title>
</head>
<body>
<?php
// Display greeting message
echo 'Hello World!';
?>
</body>
</html>

 What You Can Do with PHP 

There are lot more things you can do with PHP. 

•  You can generate dynamic pages and files. 
• You can create, open, read, write and close files on the server. 
• You can collect data from a web form such as user information, email, credit card information and much more. 
• You can send emails to the users of your website. 
• You can send and receive cookies to track the visitor of your website.
•  You can store, delete, and modify information in your database. 
• You can restrict unauthorized access to your website. 
• You can encrypt data for safe transmission over internet.

How to Update Data MySQL?

 There may be a requirement where the existing data in a MySQL table needs to be modified. You can do so by using the SQL UPDATE command. This will modify any field value of any MySQL table.

Syntax

The following code block has a generic SQL syntax of the UPDATE command to modify the data in the MySQL table −

UPDATE Syntax-

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;

Updating Data Using a PHP Script

You can use the SQL UPDATE command with or without the WHERE CLAUSE into the PHP function – mysql_query(). This function will execute the SQL command in a similar way it is executed at the mysql> prompt.

Example

The following example to update the tutorial_title field for a record having tutorial_id as 3.

<?php $dbhost
$dbhost = 'localhost:3036';
$dbuser = 'root';
$dbpass = 'rootpassword';
$conn = mysql_connect($dbhost, $dbuser, $dbpass);
if(! $conn ) {
die('Could not connect: ' . mysql_error());
}
$sql = 'UPDATE tutorials_tbl SET tutorial_title="Learning JAVA" WHERE tutorial_id=3'
SET tutorial_title="Learning JAVA"
WHERE tutorial_id=3';
mysql_select_db('TUTORIALS');
$retval = mysql_query( $sql, $conn );
if(! $retval ) {
die('Could not update data: ' . mysql_error());
}
echo "Updated data successfully\n";
mysql_close($conn);
?>

What is MYSQL?

 MySQL is a freely available open source Relational Database Management System (RDBMS) that uses Structured Query Language (SQL).

 SQL is the most popular language for adding, accessing and managing content in a database. It is most noted for its quick processing, proven reliability, ease and flexibility of use. MySQL is an essential part of almost every open source PHP application. Good examples for PHP & MySQL-based scripts are WordPress, Joomla, Magento and Drupal.

 One of the most important things about using MySQL is to have a MySQL specialized host. Here are some of the things SiteGround can offer:

• MySQL is a database system used on the web
• MySQL is a database system that runs on a server
• MySQL is ideal for both small and large applications
• MySQL is very fast, reliable, and easy to use
• MySQL uses standard SQL
• MySQL compiles on a number of platforms
• MySQL is free to download and use
• MySQL is developed, distributed, and supported by Oracle Corporation
• MySQL is named after co-founder Monty Widenius's daughter: My

Database Connectivity

<?php
$servername = "localhost";
$username = "username";
$password = "password";


$conn = new mysqli($servername, $username, $password);

if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 
echo "Connected successfully";
?>

Data Insertion in MYSQL

 To insert data into a MySQL table, you would need to use the SQL INSERT INTO command. 

You can insert data into the MySQL table by using the mysql> prompt or by using any script like PHP.

Here are some syntax rules to follow:

•  The SQL query must be quoted in PHP 

• String values inside the SQL query must be quoted

•  Numeric values must not be quoted

•  The word NULL must not be quoted

Syntax

INSERT INTO `table_name`(column_1,column_2,...) VALUES (value_1,value_2,...);

• INSERT INTO `table_name` is the command that tells MySQL server to add new row into a table named `table_name`.

• (column_1,column_2,...) specifies the columns to be updated in the  new row

• VALUES (value_1,value_2,...) specifies the values to be added into the new row

• String data types - all the string values should be enclosed in single quotes.

• Numeric data types - all numeric values should be supplied directly without enclosing them in single 
• or double quotes.

• Date data types - enclose date values in single quotes in the format 'YYYY-MM-DD'.

Inserting Data Using a PHP Script
Example

When supplying the data values to be inserted into the new table, the following should be considered while 

dealing with different data types.

You can use the same SQL INSERT INTO command into the PHP function mysql_query() to

 insert data into a MySQL table.

This example will take three parameters from the user and will insert them into the MySQL

 table −

<html>

   <head>
      <title>Add New Record in MySQL Database</title>
   </head>

   <body>
      <?php
         if(isset($_POST['add'])) {
            $dbhost = 'localhost';
            $dbuser = 'root';
            $dbpass = 'rootpassword';
            $conn = mysql_connect($dbhost, $dbuser, $dbpass);
         
            if(! $conn ) {
               die('Could not connect: ' . mysql_error());
            }

            if(! get_magic_quotes_gpc() ) {
               $tutorial_title = addslashes ($_POST['tutorial_title']);
               $tutorial_author = addslashes ($_POST['tutorial_author']);
            } else {
               $tutorial_title = $_POST['tutorial_title'];
               $tutorial_author = $_POST['tutorial_author'];
            }

            $submission_date = $_POST['submission_date'];
   
            $sql = "INSERT INTO tutorials_tbl ".
               "(tutorial_title,tutorial_author, submission_date) "."VALUES ".
               "('$tutorial_title','$tutorial_author','$submission_date')";
               mysql_select_db('TUTORIALS');
            $retval = mysql_query( $sql, $conn );
         
            if(! $retval ) {
               die('Could not enter data: ' . mysql_error());
            }
         
            echo "Entered data successfully\n";
            mysql_close($conn);
         } else {
      ?>
   
      <form method = "post" action = "<?php $_PHP_SELF ?>">
         <table width = "600" border = "0" cellspacing = "1" cellpadding = "2">
            <tr>
               <td width = "250">Tutorial Title</td>
               <td>
                  <input name = "tutorial_title" type = "text" id = "tutorial_title">
               </td>
            </tr>
         
            <tr>
               <td width = "250">Tutorial Author</td>
               <td>
                  <input name = "tutorial_author" type = "text" id = "tutorial_author">
               </td>
            </tr>
         
            <tr>
               <td width = "250">Submission Date [   yyyy-mm-dd ]</td>
               <td>
                  <input name = "submission_date" type = "text" id = "submission_date">
               </td>
            </tr>
      
            <tr>
               <td width = "250"> </td>
               <td> </td>
            </tr>
         
            <tr>
               <td width = "250"> </td>
               <td>
                  <input name = "add" type = "submit" id = "add"  value = "Add Tutorial">
               </td>
            </tr>
         </table>
      </form>
   <?php
      }
   ?>
   </body>
</html>

Item counter in owl Carousel

<script>

jQuery(document).ready(function() {

    var carousel = jQuery(".service-slider");

    jQuery(".service-slider").owlCarousel({

        items: 3,

        loop: true,

        margin: 1,

        autoplay:true,

        autoplayTimeout:2000,

        autoplayHoverPause:true,

        center: true,

        onInitialized  : counter, 

        onTranslated : counter,

        responsive: {

            0: {

                items: 1,

                nav: true,

                dots: false,

            },

            575: {

                items: 2,

                nav: true,

                dots: false,

            },

            767: {

                items: 2,

                nav: true,

                dots: false,

            },

            980: {

                items: 2,

                nav: true,

                dots: false,

            },

            1000: {

                items: 2,

                nav: true,

                dots: false,

            },

            1280: {

                items: 3,

                nav: true,

                dots: false,

            }

        },

    });

    function counter(e) {

   var ele   = e.target;        

    var items     = e.item.count;    

    var item      = e.item.index + 1;  

  if(item > items) {

    item = item - items

  }

        if(items<10){

  jQuery('#number-count').html("<span class=''>0"+item+"</span><span class='divider'> |</span><span class='all-items'> 0"+items+"</span>");

        } else{

       jQuery('#number-count').html("<span class=''>0"+item+"</span><span class='divider'> |</span><span class='all-items'>"+items+"</span>");     

        }

}

});

  </script>

Gradient Border Button CSS

<button>Gradient Border Button </button>

<style>

button {

  color: #000;

  cursor:pointer;

  font-size: 1rem;

  padding: .6rem 4rem;

  border-radius: 100rem;

  border: solid 3px transparent;

  background-origin: border-box;

  background-clip: content-box, border-box;

  box-shadow: 0 0 6px 0 rgba(157, 96, 212, 0.5);

  box-shadow: 2px 1000px 1px #fff inset;

  background-image: linear-gradient(rgba(255, 255, 255, 0), rgba(255, 255, 255, 0)), linear-gradient(101deg, #78e4ff, #ff48fa);

}

button:hover {

  color: #fff;

  box-shadow: none;

}

</style>

jQuery to smoothly scroll page

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<script>
$(document).ready(function(){
  
  $("a").on('click', function(event) {
     

if (this.hash !== "") {
    

 event.preventDefault();
     

var hash = this.hash;
     

$('html, body').animate({
       

 scrollTop: $(hash).offset().top
      

}, 800, function(){
       

window.location.hash = hash;
      

});
   

 }
  

});

});
</script>