Home Database Mysql Tutorial mysql_unbuffered_query与mysql_query的区别

mysql_unbuffered_query与mysql_query的区别

Jun 07, 2016 pm 04:23 PM
mysql query the difference

PHP mysql_data_seek() 函数 定义和用法 mysql_data_seek() 函数移动内部结果的指针。 语法 mysql_data_seek(data,row) 参数 描述 data 必需。返回类型为 resource 的结果集。该结果集从 mysql_query() 的调用中得到。 row 必需。想要设定的新的结果集指针的

  PHP mysql_data_seek() 函数

  定义和用法

  mysql_data_seek() 函数移动内部结果的指针。

  语法

  mysql_data_seek(data,row)

  参数

  描述

  data

  必需。返回类型为 resource 的结果集。该结果集从 mysql_query() 的调用中得到。

  row

  必需。想要设定的新的结果集指针的行数。0 指示第一个记录。

  说明

  mysql_data_seek() 将 data 参数指定的 MySQL 结果内部的行指针移动到指定的行号。

  接着调用 mysql_fetch_row() 将返回那一行。

  row 从 0 开始。row 的取值范围应该从 0 到 mysql_num_rows – 1。

  但是如果结果集为空(mysql_num_rows() == 0),要将指针移动到 0 会失败并发出 E_WARNING 级的错误,mysql_data_seek() 将返回 false。

  返回值

  如果成功则返回 true,失败则返回 false。

  提示和注释

  注释:mysql_data_seek() 只能和 mysql_query()一起使用,,而不能用于 mysql_unbuffered_query()。

  例子

  $conn = mysql_connect(‘localhost’,'root’,'root’);

  mysql_query(‘set names gbk’);

  mysql_select_db(‘pw8′,$conn);

  $sql = "SELECT * FROM shop_district";

  //$result = mysql_unbuffered_query($sql,$conn);

  $result = mysql_query($sql,$conn);

  while ($row = mysql_fetch_array($result, MYSQL_NUM)) {

  printf ("ID: %s FID: %s Name: %s

  ", $row[0], $row[1], $row[2]);

  }

  mysql_data_seek($result,0);

  while ($row = mysql_fetch_array($result, MYSQL_NUM)) {

  printf ("ID: %s FID: %s Name: %s

  ", $row[0], $row[1], $row[2]);

  }

 

  mysql_free_result($result);

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