略微加速

PHP官方手册 - 互联网笔记

PHP - Manual: mysqli_stmt::data_seek

2024-11-23

mysqli_stmt::data_seek

mysqli_stmt_data_seek

(PHP 5, PHP 7, PHP 8)

mysqli_stmt::data_seek -- mysqli_stmt_data_seekSeeks to an arbitrary row in statement result set

说明

面向对象风格

public mysqli_stmt::data_seek(int $offset): void

过程化风格

mysqli_stmt_data_seek(mysqli_stmt $statement, int $offset): void

Seeks to an arbitrary result pointer in the statement result set.

mysqli_stmt_store_result() must be called prior to mysqli_stmt_data_seek().

参数

statement

仅以过程化样式:由 mysqli_stmt_init() 返回的 mysqli_stmt 对象。

offset

Must be between zero and the total number of rows minus one (0.. mysqli_stmt_num_rows() - 1).

返回值

没有返回值。

范例

示例 #1 面向对象风格

<?php
/* Open a connection */
$mysqli = new mysqli("localhost""my_user""my_password""world");

/* check connection */
if (mysqli_connect_errno()) {
    
printf("Connect failed: %s\n"mysqli_connect_error());
    exit();
}

$query "SELECT Name, CountryCode FROM City ORDER BY Name";
if (
$stmt $mysqli->prepare($query)) {

    
/* execute query */
    
$stmt->execute();

    
/* bind result variables */
    
$stmt->bind_result($name$code);

    
/* store result */
    
$stmt->store_result();

    
/* seek to row no. 400 */
    
$stmt->data_seek(399);

    
/* fetch values */
    
$stmt->fetch();

    
printf ("City: %s  Countrycode: %s\n"$name$code);

    
/* close statement */
    
$stmt->close();
}

/* close connection */
$mysqli->close();
?>

示例 #2 过程化风格

<?php
/* Open a connection */
$link mysqli_connect("localhost""my_user""my_password""world");

/* check connection */
if (mysqli_connect_errno()) {
    
printf("Connect failed: %s\n"mysqli_connect_error());
    exit();
}

$query "SELECT Name, CountryCode FROM City ORDER BY Name";
if (
$stmt mysqli_prepare($link$query)) {

    
/* execute query */
    
mysqli_stmt_execute($stmt);

    
/* bind result variables */
    
mysqli_stmt_bind_result($stmt$name$code);

    
/* store result */
    
mysqli_stmt_store_result($stmt);

    
/* seek to row no. 400 */
    
mysqli_stmt_data_seek($stmt399);

    
/* fetch values */
    
mysqli_stmt_fetch($stmt);

    
printf ("City: %s  Countrycode: %s\n"$name$code);

    
/* close statement */
    
mysqli_stmt_close($stmt);
}

/* close connection */
mysqli_close($link);
?>

以上例程会输出:

City: Benin City  Countrycode: NGA

参见

add a noteadd a note

User Contributed Notes 1 note

up
1
phpnet at stuffonmylaptop dot com
10 years ago
Although the documentation says you must provide a number between 0 and count - 1, you can actually supply a negative number, which appears to be cast to positive (such as in abs()).

For example:

<?php
$db
= new mysqli('localhost', 'test', 'password', 'schema');
$db->multi_query("
            SELECT * FROM
            (
                SELECT 1 as 'position'
                UNION SELECT 2 as 'position'
                UNION SELECT 3 as 'position'
                UNION SELECT 4 as 'position'
                UNION SELECT 5 as 'position'
            ) as rows"
);
           
$result = $db->store_result();

for (
$i = 0; $i < $result->num_rows; $i++)
{
   
$offset = $i;
   
$result->data_seek($offset);
   
var_dump("Seek offset is: {$offset}", $result->fetch_object());
}

for (
$i = 0; $i < $result->num_rows; $i++)
{
   
$offset = -$i;
   
$result->data_seek($offset);
   
var_dump("Seek offset is: {$offset}", $result->fetch_object());
}

官方地址:https://www.php.net/manual/en/mysqli-stmt.data-seek.php

北京半月雨文化科技有限公司.版权所有 京ICP备12026184号-3