Use mysqli_num_fields() in php to query the number of fields

php requires frequent connection to the database. mysqli is a way to connect to the database in php. Sometimes we need to query the number of fields in the table in the database. This article will take you to take a look at the mysqli_num_fields() method.

1.Connect to the database

<?php
$servername="localhost";
$username="root";
$password="root123456";
$dbname="my_database";
$link = mysqli_connect($servername, $username, $password, $dbname);
if (mysqli_connect_errno()) {
    printf("连接失败: %s\n", mysqli_connect_error());
    exit();
}

2.Query the number of fields

$sql="select * from fate";
if ($result = mysqli_query($link,$sql)) {
    $row = mysqli_num_fields($result);
    printf("数据库中的字段.%d\n", $row);
    mysqli_free_result($result);
}
mysqli_close($link);

输出：数据库中的字段.3

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