How can the PHP code be optimized to ensure accurate and consistent output when generating bar charts from database results?

When generating bar charts from database results in PHP, it is important to ensure that the data is properly sanitized and validated to prevent any unexpected behavior or errors. One way to optimize the code is to use prepared statements to interact with the database, ensuring data integrity and security. Additionally, using a reliable charting library like Chart.js can help in creating visually appealing and accurate bar charts. 

// Assuming $db is the database connection object

// Retrieve data from the database using prepared statements
$stmt = $db->prepare("SELECT category, value FROM chart_data");
$stmt->execute();
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);

// Generate data arrays for the chart
$categories = [];
$values = [];
foreach ($results as $row) {
    $categories[] = $row['category'];
    $values[] = $row['value'];
}

// Include Chart.js library
echo '<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>';

// Create a bar chart using Chart.js
echo '<canvas id="myChart"></canvas>';
echo '<script>';
echo 'var ctx = document.getElementById("myChart").getContext("2d");';
echo 'var myChart = new Chart(ctx, {';
echo '    type: "bar",';
echo '    data: {';
echo '        labels: ' . json_encode($categories) . ',';
echo '        datasets: [{';
echo '            label: "Chart Data",';
echo '            data: ' . json_encode($values) . ',';
echo '            backgroundColor: "rgba(54, 162, 235, 0.2)",';
echo '            borderColor: "rgba(54, 162, 235, 1)",';
echo '            borderWidth: 1';
echo '        }]';
echo '    },';
echo '    options: {';
echo '        scales: {';
echo '            y: {';
echo '                beginAtZero: true';
echo '            }';
echo '        }';
echo '    }';
echo '});';
echo '</script>';

Keywords

PHP optimization bar charts database output

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