mysqli_result::$field_count
mysqli_result::$field_count
mysqli_num_fields
(PHP 5, PHP 7)
mysqli_result :: $ field_count -- mysqli_num_fields -- 获取结果中的字段数
描述
面向对象的风格
int $mysqli_result->field_count;
程序风格
int mysqli_num_fields ( mysqli_result $result )
返回指定结果集中的字段数。
参数
`result`
仅过程风格：由mysqli_query（），mysqli_store_result（）或mysqli_use_result（）返回的结果集标识符。
返回值
结果集中的字段数。
例子
Example＃1面向对象的风格
<?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(
?>
示例＃2程序风格
<?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
?>
上面的例子会输出：
Result set has 5 fields.
- mysqli_fetch_field（） - 返回结果集中的下一个字段
← mysqli_result::fetch_row
mysqli_result::field_seek →
