mysqli_result::$field_count
(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 →
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