php判断mysql是否为空值

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

// 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);
}

// 执行查询
$sql = "SELECT * FROM table_name WHERE condition";
$result = $conn->query($sql);

// 判断结果集是否为空
if ($result->num_rows > 0) {
    // 输出数据
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - Name: " . $row["name"]. "<br>";
    }
} else {
    echo "0 结果";
}

// 关闭连接
$conn->close();
?>

while($row = $result->fetch_assoc()) {
    if (isset($row["column_name"]) && !empty($row["column_name"])) {
        // 处理非空值
    } else {
        // 处理空值
    }
}