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# mysqli_num_fields

(PHP 5)

mysqli_num_fields

(no version information, might be only in CVS)

result->field_count -- Get the number of fields in a result

## Description

Procedural style:

int mysqli_num_fields ( mysqli_result result )

Object oriented style (property):

class mysqli_result {
int field_count
}

mysqli_num_fields() returns the number of fields from specified result set.

## 返回值

The number of fields from a result set

## 参见

mysqli_fetch_field().

## 范例

例子 1. Object oriented style

`<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
if ($result = $mysqli->query("SELECT * FROM City ORDER BY ID LIMIT 1")) {
/* determine number of fields in result set */
$field_cnt = $result->field_count;
printf("Result set has %d fields.\n", $field_cnt);
/* close result set */
$result->close();
}
/* close connection */
$mysqli->close();
?>`

例子 2. Procedural style

`<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
if ($result = mysqli_query($link, "SELECT * FROM City ORDER BY ID LIMIT 1")) {
/* determine number of fields in result set */
$field_cnt = mysqli_num_fields($result);
printf("Result set has %d fields.\n", $field_cnt);
/* close result set */
mysqli_free_result($result);
}
/* close connection */
mysqli_close($link);
?>`

上例将输出：

    Result set has 5 fields.

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