PHP mysqli_fetch_field_direct() 函数

实例

返回结果集中某个单一字段（列）的 meta-data，并输出字段名称、表格和最大长度：

 <?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))
 {
 // Get field information for "Age"
 $fieldinfo=mysqli_fetch_field_direct($result,1);

 printf("Name: %sn",$fieldinfo->name);
 printf("Table: %sn",$fieldinfo->table);
 printf("max. Len: %dn",$fieldinfo->max_length);

 // Free result set
 mysqli_free_result($result);
}

mysqli_close($con);
 ?>