PHP mysqli_num_fields() 函数
2018-12-08 18:00 更新
PHP mysqli_num_fields() 函数
实例
返回结果集中字段(列)的数量:
<?php
$con=mysqli_connect("localhost","my_user","my_password","my_db");
// Check connection
if (mysqli_connect_errno($con))
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sql="SELECT Lastname,Age FROM Persons ORDER BY Lastname";
if ($result=mysqli_query($con,$sql))
{
// Return the number of fields in result set
$fieldcount=mysqli_num_fields($result);
printf("Result set has %d fields.n",$fieldcount);
// Free result set
mysqli_free_result($result);
}
mysqli_close($con);
?>
$con=mysqli_connect("localhost","my_user","my_password","my_db");
// Check connection
if (mysqli_connect_errno($con))
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sql="SELECT Lastname,Age FROM Persons ORDER BY Lastname";
if ($result=mysqli_query($con,$sql))
{
// Return the number of fields in result set
$fieldcount=mysqli_num_fields($result);
printf("Result set has %d fields.n",$fieldcount);
// Free result set
mysqli_free_result($result);
}
mysqli_close($con);
?>
定义和用法
mysqli_num_fields() 函数返回结果集中字段(列)的数量。
语法
mysqli_num_fields(result);
参数 | 描述 |
---|---|
result | 必需。规定由 mysqli_query()、mysqli_store_result() 或 mysqli_use_result() 返回的结果集标识符。 |
技术细节
返回值: | 返回结果集中字段的数量。 |
---|---|
PHP 版本: | 5+ |
PHP MySQLi 参考手册
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