field_seek

❮ PHP MySQLi 参考手册

示例 - 面向对象的样式

设置结果集中第二个字段（"Age"）的字段指针，然后通过 mysqli_fetch_field() 获取字段信息并输出字段名称、表格和最大长度:

<?php
$mysqli = new mysqli("localhost","my_user","my_password","my_db");

if ($mysqli -> connect_errno) {
  echo "Failed to connect to MySQL: " . $mysqli -> connect_error;
  exit();
}

$sql = "SELECT Lastname, Age FROM Persons ORDER BY Lastname";

if ($result = $mysqli -> query($sql)) {

  // Get field information for second column
  $result = field_seek(1);
  $fieldinfo = $result -> fetch_field();

  printf("Name: %s\n", $fieldinfo -> name);
  printf("Table: %s\n", $fieldinfo -> table);
  printf("Max. Len: %d\n", $fieldinfo -> max_length);
  $result -> free_result();
}

$mysqli -> close();
?>

查看底部的程序样式示例。

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定义和用法

field_seek() / mysqli_field_seek() 函数把字段指针设置为指定字段的偏移量。

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语法

面向对象的风格:

$mysqli_result -> field_seek(fieldnr)

程序风格:

mysqli_field_seek(result, fieldnr)

参数值

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。

技术细节

返回值:	若成功则返回 TRUE，若失败则返回 FALSE。
PHP 版本:	5+

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示例 - 程序样式

设置结果集中第二个字段（"Age"）的字段指针，然后通过 mysqli_fetch_field() 获取字段信息并输出字段名称、表格和最大长度:

<?php
$con = mysqli_connect("localhost","my_user","my_password","my_db");

if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  exit();
}

$sql="SELECT Lastname, Age FROM Persons ORDER BY Lastname";

if ($result = mysqli_query($con,$sql)) {

  // Get field information for second column
  mysqli_field_seek($result, 1);
  $fieldinfo = mysqli_fetch_field($result);

  printf("Name: %s\n", $fieldinfo -> name);
  printf("Table: %s\n", $fieldinfo -> table);
  printf("max. Len: %d\n", $fieldinfo -> max_length);
  mysqli_free_result($result);
}

mysqli_close($con);
?>

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❮ PHP MySQLi 参考手册