mysqli_result::$field_count

mysqli_num_fields

(PHP 5, PHP 7, PHP 8)

mysqli_result::$field_count -- mysqli_num_fields — Gets the number of fields in the result set

说明

面向对象风格

int $mysqli_result->field_count;

过程化风格

mysqli_num_fields(mysqli_result $result): int

Returns the number of fields in the result set.

参数

result: 仅以过程化样式：由 mysqli_query()、mysqli_store_result()、 mysqli_use_result()、mysqli_stmt_get_result() 返回的 mysqli_result 对象。

返回值

An int representing the number of fields.

示例

示例 #1 面向对象风格

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

$result = $mysqli->query("SELECT Name, CountryCode, District, Population FROM City ORDER BY ID LIMIT 1");

/* Get the number of fields in the result set */
$field_cnt = $result->field_count;

printf("Result set has %d fields.\n", $field_cnt);

示例 #2 过程化风格

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = mysqli_connect("localhost", "my_user", "my_password", "world");

$result = mysqli_query($link, "SELECT Name, CountryCode, District, Population FROM City ORDER BY ID LIMIT 1");

/* Get the number of fields in the result set */
$field_cnt = mysqli_num_fields($result);

printf("Result set has %d fields.\n", $field_cnt);

以上示例会输出：

Result set has 4 fields.

参见

mysqli_fetch_field() - Returns the next field in the result set