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PHP mysqli_fetch_field_direct () function

PHP MySQLi Reference Manual PHP MySQLi Reference Manual

Returns a single result set fields (columns) of meta-data, and outputs the field name, and the maximum length of the table: 

<?php 
// 假定数据库用户名：root，密码：123456，数据库：w3big 
$con=mysqli_connect("localhost","root","123456","w3big"); 
if (mysqli_connect_errno($con)) 
{ 
    echo "连接 MySQL 失败: " . mysqli_connect_error(); 
} 

$sql="SELECT name,url FROM websites ORDER BY alexa";


if ($result=mysqli_query($con,$sql))
{
// 获取字段 "name" 的信息
$fieldinfo=mysqli_fetch_field_direct($result,1);

printf("字段名: %s",$fieldinfo->name);
echo "<br>";
printf("数据表: %s",$fieldinfo->table);
echo "<br>";
printf("最大长度: %d",$fieldinfo->max_length);

// 释放结果集
mysqli_free_result($result);
}

mysqli_close($con);
?>

Definition and Usage

mysqli_fetch_field_direct () function to obtain a single centralized field from the results (column) of meta-data, and return as an object.

grammar

mysqli_fetch_field_direct( result,fieldnr ) ;

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。
fieldnr 必需。规定字段号。必须介于 0 和 字段数-1 之间。

technical details

return value: Returns an object that contains field definition information. If no information is available it returns FALSE. This object has the following properties:
  • name - the name of the column
  • orgname - original column name (if you specify an alias)
  • table - a table name
  • orgtable - the original name of the table (if you specify an alias)
  • def - The default value for this field
  • The maximum width of the field - max_length
  • length - specified in the table definition field width
  • Character Set number field - charsetnr
  • Flag field - flags
  • type - data type for the field
  • decimals - integer field digits after the decimal point
PHP version: 5+

PHP MySQLi Reference Manual PHP MySQLi Reference Manual