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);
?>

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>