Use PHP function 'mysqli_fetch_assoc' to get a row from the result set as an associative array

Use the PHP function "mysqli_fetch_assoc" to get a row from the result set as an associative array

In PHP, interacting with the database is a common task. When we execute a SELECT query and get the result set, we usually need to store the data in the result set into a PHP array for further processing.

PHP provides multiple functions to process result sets, one of the commonly used functions is "mysqli_fetch_assoc". This function obtains a row from the result set as an associative array, allowing us to access data based on field names.

The following is a sample code that demonstrates how to use the "mysqli_fetch_assoc" function to get a row of data from the result set:

<?php
// 连接到数据库
$mysqli = new mysqli("localhost", "username", "password", "database");

// 检查连接是否成功
if ($mysqli->connect_errno) {
    echo "连接数据库失败：" . $mysqli->connect_error;
    exit();
}

// 执行SELECT查询
$result = $mysqli->query("SELECT * FROM users");

// 检查是否有数据返回
if ($result->num_rows > 0) {
    // 使用mysqli_fetch_assoc函数获取一行数据
    $row = mysqli_fetch_assoc($result);

    // 输出关联数组的值
    echo "ID: " . $row['id'] . "<br>";
    echo "姓名: " . $row['name'] . "<br>";
    echo "年龄: " . $row['age'] . "<br>";
} else {
    echo "没有查询到数据。";
}

// 关闭数据库连接
$mysqli->close();
?>

In the above example, we first connect to the database through the "new mysqli" function , and check whether the connection is successful. Then we execute the SELECT query and store the results in the variable $result. Then we use the "mysqli_fetch_assoc" function to get a row of data from the result set and store it in the variable $row. Finally, we access the data by field name through the $row array and output it to the page.

It should be noted that each call of the "mysqli_fetch_assoc" function will return the next row of data in the result set. If there is no more data to obtain, it will return null. Therefore, if we wish to fetch multiple rows of data, we can do so by calling the "mysqli_fetch_assoc" function multiple times in a loop.

Using the "mysqli_fetch_assoc" function allows us to easily obtain a row of data from the result set as an associative array and access the data based on the field name. It is very useful when processing database query results and can improve the readability and maintainability of code.

To summarize, through the sample code in this article, you can learn how to use the PHP function "mysqli_fetch_assoc" to get a row from the result set as an associative array. Hope this helps you in your development process!

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