mysql sql动态条件查询

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 用户输入的条件
$keyword = $_GET['keyword'] ?? '';
$dateFrom = $_GET['dateFrom'] ?? '';
$dateTo = $_GET['dateTo'] ?? '';

// 构建动态查询条件
$sql = "SELECT * FROM myTable WHERE 1=1";
if (!empty($keyword)) {
    $sql .= " AND name LIKE '%" . $conn->real_escape_string($keyword) . "%'";
}
if (!empty($dateFrom)) {
    $sql .= " AND date >= '" . $conn->real_escape_string($dateFrom) . "'";
}
if (!empty($dateTo)) {
    $sql .= " AND date <= '" . $conn->real疏散字符串($dateTo) . "'";
}

// 执行查询
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // 输出数据
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - Name: " . $row["name"]. " - Date: " . $row["date"]. "<br>";
    }
} else {
    echo "0 结果";
}
$conn->close();
?>