How can prepared statements enhance security and performance in PHP UPDATE queries?

Prepared Statements for Update Queries

In PHP, preparing statements is crucial for enhancing query security and performance. Prepared statements allow for parameterized queries, where placeholders (?) are used instead of direct variable insertion.

Example for UPDATE Queries

Consider the following mysqli query that updates data in the Applicant table:

$db_usag->query("UPDATE Applicant SET phone_number ='$phone_number',
street_name='$street_name', city='$city', county='$county', zip_code='$zip_code', day_date='$day_date', month_date='$month_date',
 year_date='$year_date' WHERE account_id='$account_id'");

To prepare this statement, replace all variable assignments with placeholders:

<code class="php">$sql = "UPDATE Applicant SET phone_number=?, street_name=?, city=?, county=?,
zip_code=?, day_date=?, month_date=?, year_date=? WHERE account_id=?";</code>

Next, initialize a prepared statement object:

<code class="php">$stmt = $db_usag->prepare($sql);</code>

Bind parameters to the statement using the bind_param() method. Specify the data types of the parameters accordingly:

<code class="php">// Assuming the date and account_id parameters are integers `d` and the rest are strings `s`
$stmt->bind_param('sssssdddd', $phone_number, $street_name, $city, $county,
$zip_code, $day_date, $month_date, $year_date, $account_id);</code>

Execute the prepared statement:

<code class="php">$stmt->execute();</code>

Check for any errors:

<code class="php">if ($stmt->error) {
    echo "FAILURE!!! " . $stmt->error;
}</code>

If the execution was successful, retrieve the number of affected rows:

<code class="php">echo "Updated {$stmt->affected_rows} rows";</code>

Finally, close the statement object:

<code class="php">$stmt->close();</code>

By using prepared statements, you can avoid potential injection attacks and improve the efficiency of your database queries.

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