PHP MySQLi Update Data

This article is created to describe the way to update or modify specific data using PHP MySQLi script. These are the two approaches, that can be used to update any specific or all data in the database:

• Using PHP MySQLi Object-Oriented Script
• Using PHP MySQLi Procedural Script

Whatever the approach we choose to update the data. We need to follow these simple steps:

• Open a connection to the database
• Write an SQL statement regarding the data modification
• Initialize the written SQL statement to a variable
• Use this variable to perform the query against the database, to modify particular data
• Close the database connection

The SQL statement to update specific data is:

UPDATE tableName
SET column1=value1, column2=value2, column3=value3, ..., columnN=valueN
WHERE particularColumn=particularValue;

Important - Be aware while updating the data. The WHERE clause is used when we need to update particular record(s).

Be Aware - Omitting the WHERE clause, update all records in the table. Indirectly, deletes all the previous records, so be aware.

Update Data using PHP MySQLi Object-Oriented Script

To update particular data (record or row) using PHP MySQLi object-oriented script, follow the example given below. In this example, I am going to update age of record whose id is 3:

<?php
   $servername = "localhost";
   $username = "root";
   $password = "";
   $dbname = "codescracker";
   
   $conn = new mysqli($servername, $username, $password, $dbname);
   
   if($conn->connect_errno)
   {
      echo "Connection to the database failed!<BR>";
      echo "Reason: ", $conn->connect_error;
      exit();
   }
   
   $sql = "UPDATE customer SET age='40' WHERE id=3";
   
   $result = $conn->query($sql);
   if($result)
   {
      echo "Data updated successfully.";
      
      // block of code, to process further...
   }
   else
   {
      echo "Error occurred while updating the record!<BR>";
      echo "Reason: ", $conn->error;
   }
   $conn->close();
?>

Before executing the above PHP script, here is the snapshot of the table customer:

Here is the output produced by above PHP example, on updating the record using PHP MySQLi object-oriented script:

And following is the snapshot of the table named student after executing the above PHP script:

Note - The mysqli() is used to open a connection to the MySQL database server, in object-oriented style.

Note - The new keyword is used to create a new object.

Note - The connect_errno is used to get/return the error code (if any) from last connect call, in object-oriented style.

Note - The connect_error is used to get the error description (if any) from last connection, in object-oriented style.

Note - The exit() is used to terminate the execution of the current PHP script.

Note - The query() is used to perform query on the MySQL database, in object-oriented style.

Note - The error is used to return the description of error (if any), by the most recent function call, in object-oriented style.

Note - The close() is used to close an opened connection, in object-oriented style.

Note - If you remove the WHERE clause from above PHP script, then the age column of all rows will set to 40.

The above example, can also be written as:

<?php
   $conn = new mysqli("localhost", "root", "", "codescracker");
   
   if(!$conn->connect_errno)
   {
      if($conn->query("UPDATE customer SET age='40' WHERE id=3"))
         echo "Data updated successfully.";
   }
   $conn->close();
?>

Update Data using PHP MySQLi Procedural Script

To update data using PHP MySQLi procedural script, follow the example given below:

<?php
   $conn = mysqli_connect("localhost", "root", "", "codescracker");
   
   if(!mysqli_connect_errno())
   {
      $sql = "UPDATE customer SET age='42' WHERE id=3";
      
      if(mysqli_query($conn, $sql))
         echo "Data updated successfully.";
      else
      {
         echo "Error occurred while updating the record!<BR>";
         echo "Reason: ", mysqli_error($conn);
      }
   }
   mysqli_close($conn);
?>

Note - The mysqli_connect() is used to open a connection to the MySQL database server, in procedural style.

Note - The mysqli_connect_errno() is used to get/return the error code (if any) from last connect call, in procedural style.

Note - The mysqli_query() is used to perform query on the MySQL database, in procedural style.

Note - The mysqli_error() is used to return the description of error (if any), by the most recent function call, in object-oriented style.

Note - The mysqli_close() is used to close an opened connection to the MySQL database, in procedural style.

PHP MySQLi Object-Oriented - Update Multiple Columns

To update multiple columns at once, everything will be same as done in the section Update Data using PHP MySQLi Object-Oriented Script, except the SQL statement. That is, to update two columns say age and email, use the following SQL statement:

$sql = "UPDATE customer SET age='42', email='newmail@xyz.com' WHERE id=3";

And to update more columns, say three columns, use following SQL statement:

$sql = "UPDATE customer SET name='Lucas', age='42', email='newmail@xyz.com' WHERE id=3";

Here is the complete PHP MySQLi script to update multiple columns at once:

<?php
   $conn = new mysqli("localhost", "root", "", "codescracker");
   
   if(!$conn->connect_errno)
   {
      $sql = "UPDATE customer SET name='Lucas', age='42', email='newmail@xyz.com' WHERE id=3";
      
      if($conn->query($sql))
         echo "Data updated successfully.";
      else
      {
         echo "Error occurred while updating the record!<BR>";
         echo "Reason: ", $conn->error;
      }
   }
   $conn->close();
?>

PHP MySQLi Procedural - Update Multiple Columns

<?php
   $conn = mysqli_connect("localhost", "root", "", "codescracker");
   
   if(!mysqli_connect_errno())
   {
      $sql = "UPDATE customer SET name='Lucas', age='42', email='newmail@xyz.com' WHERE id=3";
      
      if(mysqli_query($conn, $sql))
         echo "Data updated successfully.";
      else
      {
         echo "Error occurred while updating the record!<BR>";
         echo "Reason: ", mysqli_error($conn);
      }
   }
   mysqli_close($conn);
?>

PHP MySQLi - Update All Rows at Once

To update all rows using PHP MySQLi script, all the process will be same, except that, remove/omit the WHERE clause. That is, to update all rows with particular columns, use this similar SQL statement:

$sql = "UPDATE customer SET email='newmail@xyz.com'";

And to update all rows with multiple columns, use this similar SQL statement:

$sql = "UPDATE customer SET name='Lucas', age='42', email='newmail@xyz.com'";

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