animation/nested_loop.html at main · enhancedformysql/animation · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>MySQL Nested Loop Join Visualization</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            margin: 20px;
        }
        .container {
            display: flex;
            justify-content: space-between;
            margin-bottom: 20px;
        }
        .table-container {
            width: 45%;
            border: 1px solid #ddd;
            padding: 10px;
            border-radius: 5px;
        }
        .result-container {
            width: 100%;
            border: 1px solid #ddd;
            padding: 10px;
            border-radius: 5px;
            margin-top: 20px;
            min-height: 100px;
        }
        table {
            width: 100%;
            border-collapse: collapse;
        }
        th, td {
            border: 1px solid #ddd;
            padding: 8px;
            text-align: left;
        }
        th {
            background-color: #f2f2f2;
        }
        .highlight {
            background-color: #ffeb3b;
            transition: background-color 0.3s;
        }
        .matched {
            background-color: #a5d6a7;
            transition: background-color 0.3s;
        }
        .controls {
            margin: 20px 0;
        }
        button {
            padding: 8px 16px;
            margin-right: 10px;
            cursor: pointer;
        }
        .arrow {
            position: absolute;
            width: 100px;
            height: 2px;
            background-color: red;
            top: 50%;
            left: 50%;
            transform-origin: left center;
            display: none;
        }
        .arrow::after {
            content: '';
            position: absolute;
            right: 0;
            top: -4px;
            width: 0;
            height: 0;
            border-left: 8px solid red;
            border-top: 5px solid transparent;
            border-bottom: 5px solid transparent;
        }
        .explanation {
            margin: 20px 0;
            padding: 15px;
            background-color: #f8f9fa;
            border-radius: 5px;
        }
    </style>
</head>
<body>
    <h1>MySQL Nested Loop Join Visualization</h1>

    <div class="explanation">
        <h3>How Nested Loop Join Works:</h3>
        <ol>
            <li>For each row in the <strong>outer table</strong> (driving table):</li>
            <li>Scan through all rows in the <strong>inner table</strong> (driven table)</li>
            <li>If the join condition matches, combine the rows and add to results</li>
            <li>Repeat until all outer table rows are processed</li>
        </ol>
        <p><strong>Performance Note:</strong> This algorithm is O(M*N) where M and N are the table sizes. Indexes on join columns can optimize this.</p>
    </div>

    <div class="controls">
        <button id="startBtn">Start Animation</button>
        <button id="resetBtn">Reset</button>
        <button id="stepBtn">Step Through</button>
        <div>
            <label>Animation Speed: </label>
            <input type="range" id="speedSlider" min="100" max="2000" value="500">
            <span id="speedValue">500ms</span>
        </div>
    </div>

    <div class="container">
        <div class="table-container" id="outerTableContainer">
            <h3>Outer Table (Driving Table) - Employees</h3>
            <table id="outerTable">
                <thead>
                    <tr>
                        <th>id</th>
                        <th>name</th>
                        <th>dept_id</th>
                    </tr>
                </thead>
                <tbody>
                    <tr data-id="1">
                        <td>1</td>
                        <td>Alice</td>
                        <td>101</td>
                    </tr>
                    <tr data-id="2">
                        <td>2</td>
                        <td>Bob</td>
                        <td>102</td>
                    </tr>
                    <tr data-id="3">
                        <td>3</td>
                        <td>Charlie</td>
                        <td>101</td>
                    </tr>
                </tbody>
            </table>
        </div>

        <div class="table-container" id="innerTableContainer">
            <h3>Inner Table (Driven Table) - Departments</h3>
            <table id="innerTable">
                <thead>
                    <tr>
                        <th>dept_id</th>
                        <th>dept_name</th>
                    </tr>
                </thead>
                <tbody>
                    <tr data-id="101">
                        <td>101</td>
                        <td>Engineering</td>
                    </tr>
                    <tr data-id="102">
                        <td>102</td>
                        <td>Marketing</td>
                    </tr>
                    <tr data-id="103">
                        <td>103</td>
                        <td>Finance</td>
                    </tr>
                </tbody>
            </table>
        </div>
    </div>

    <div class="result-container">
        <h3>Join Result (employees JOIN departments ON dept_id)</h3>
        <table id="resultTable">
            <thead>
                <tr>
                    <th>emp_id</th>
                    <th>emp_name</th>
                    <th>dept_id</th>
                    <th>dept_name</th>
                </tr>
            </thead>
            <tbody></tbody>
        </table>
    </div>

    <div class="arrow" id="arrow"></div>

    <script>
        const outerTable = document.getElementById('outerTable');
        const innerTable = document.getElementById('innerTable');
        const resultTable = document.getElementById('resultTable').querySelector('tbody');
        const startBtn = document.getElementById('startBtn');
        const resetBtn = document.getElementById('resetBtn');
        const stepBtn = document.getElementById('stepBtn');
        const speedSlider = document.getElementById('speedSlider');
        const speedValue = document.getElementById('speedValue');
        const arrow = document.getElementById('arrow');

        let outerRows = Array.from(outerTable.querySelectorAll('tbody tr'));
        let innerRows = Array.from(innerTable.querySelectorAll('tbody tr'));
        let currentOuterIndex = 0;
        let currentInnerIndex = 0;
        let isRunning = false;
        let animationInterval;
        let speed = 500;

        speedSlider.addEventListener('input', function() {
            speed = parseInt(this.value);
            speedValue.textContent = speed + 'ms';
            if (isRunning) {
                clearInterval(animationInterval);
                startAnimation();
            }
        });

        startBtn.addEventListener('click', function() {
            if (!isRunning) {
                startAnimation();
            } else {
                pauseAnimation();
            }
        });

        resetBtn.addEventListener('click', resetAnimation);
        stepBtn.addEventListener('click', stepAnimation);

        function startAnimation() {
            isRunning = true;
            startBtn.textContent = 'Pause';
            animationInterval = setInterval(stepAnimation, speed);
        }

        function pauseAnimation() {
            isRunning = false;
            startBtn.textContent = 'Resume';
            clearInterval(animationInterval);
        }

        function resetAnimation() {
            pauseAnimation();

            // Reset highlights
            outerRows.forEach(row => row.classList.remove('highlight'));
            innerRows.forEach(row => row.classList.remove('matched', 'highlight'));

            // Clear result table
            resultTable.innerHTML = '';

            // Reset pointers
            currentOuterIndex = 0;
            currentInnerIndex = 0;

            // Hide arrow
            arrow.style.display = 'none';
        }

        function stepAnimation() {
            // Clear previous highlights
            outerRows.forEach(row => row.classList.remove('highlight'));
            innerRows.forEach(row => row.classList.remove('matched', 'highlight'));

            // If we've processed all outer rows, finish
            if (currentOuterIndex >= outerRows.length) {
                pauseAnimation();
                return;
            }

            // Highlight current outer row
            const currentOuterRow = outerRows[currentOuterIndex];
            currentOuterRow.classList.add('highlight');

            // Show arrow from outer to inner table
            const outerRect = currentOuterRow.getBoundingClientRect();
            const innerContainerRect = document.getElementById('innerTableContainer').getBoundingClientRect();

            arrow.style.display = 'block';
            arrow.style.left = (outerRect.right + 10) + 'px';
            arrow.style.top = (outerRect.top + outerRect.height / 2) + 'px';
            arrow.style.width = (innerContainerRect.left - outerRect.right - 20) + 'px';

            // Get outer row's dept_id
            const outerDeptId = currentOuterRow.querySelector('td:nth-child(3)').textContent;

            // If we've scanned all inner rows, move to next outer row
            if (currentInnerIndex >= innerRows.length) {
                currentOuterIndex++;
                currentInnerIndex = 0;
                return;
            }

            // Highlight current inner row
            const currentInnerRow = innerRows[currentInnerIndex];
            currentInnerRow.classList.add('highlight');

            // Get inner row's dept_id
            const innerDeptId = currentInnerRow.querySelector('td:first-child').textContent;

            // Check for match
            if (outerDeptId === innerDeptId) {
                currentInnerRow.classList.add('matched');

                // Add to result table
                const newRow = document.createElement('tr');
                newRow.innerHTML = `
                    <td>${currentOuterRow.querySelector('td:nth-child(1)').textContent}</td>
                    <td>${currentOuterRow.querySelector('td:nth-child(2)').textContent}</td>
                    <td>${outerDeptId}</td>
                    <td>${currentInnerRow.querySelector('td:nth-child(2)').textContent}</td>
                `;
                resultTable.appendChild(newRow);
            }

            // Move to next inner row
            currentInnerIndex++;

            // If we've finished scanning inner table, move to next outer row
            if (currentInnerIndex >= innerRows.length) {
                setTimeout(() => {
                    currentOuterIndex++;
                    currentInnerIndex = 0;
                }, speed / 2);
            }
        }

        // Initialize
        resetAnimation();
    </script>
</body>
</html>