mysqli_num_fields

Get the number of fields in a result (PHP 5)
int mysqli_num_fields ( mysqli_result result )

Procedural style:

Object oriented style (property):

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

范例

例 1307. 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 1308. 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.