What is Update query in Mysqli?

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

Syntax

Here is generic SQL syntax of UPDATE command to modify data into MySQLi table −

UPDATE table_name SET field1 = new-value1, field2 = new-value2 [WHERE Clause]

• You can update one or more field altogether.
• You can specify any condition using WHERE clause.
• You can update values in a single table at a time.

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

Updating Data from Command Prompt

This will use SQL UPDATE command with WHERE clause to update selected data into MySQLi table tutorials_inf.

Example

Following example will update name field for a record having tutorial_inf.

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

mysql> use TUTORIALS;
Database changed

mysql> UPDATE tutorials_inf 
   -> SET name = 'johar' 
   -> WHERE name = 'sai';
Query OK, 1 row affected (0.04 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql>

Updating Data Using PHP Script

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

Example

Try out the following example to update name field for a record.

<?php
   $dbhost = 'localhost:3306';
   $dbuser = 'root';
   $dbpass = '';
   $dbname = 'TUTORIALS';
   $conn = mysqli_connect($dbhost, $dbuser, $dbpass,$dbname);
   
   if(! $conn ) {
      die('Could not connect: ' . mysqli_error());
   }
   echo 'Connected successfully<br>';
   $sql = ' UPDATE tutorials_inf SET name="althamas" WHERE name="ram"';
   
   if (mysqli_query($conn, $sql)) {
      echo "Record updated successfully";
   } else {
      echo "Error updating record: " . mysqli_error($conn);
   }
   mysqli_close($conn);
?>

The sample output should be like this −

Connected successfully
Record updated successfully