mysqli_result::data_seek

mysqli_data_seek

(PHP 5, PHP 7, PHP 8)

mysqli_result::data_seek -- mysqli_data_seekAdjusts the result pointer to an arbitrary row in the result

说明

面向对象风格

public mysqli_result::data_seek(int $offset): bool

过程化风格

mysqli_data_seek(mysqli_result $result, int $offset): bool

The mysqli_data_seek() function seeks to an arbitrary result pointer specified by the offset in the result set.

参数

result

仅以过程化样式:由 mysqli_query()mysqli_store_result()mysqli_use_result()mysqli_stmt_get_result() 返回的结果集标识。

offset

The field offset. Must be between zero and the total number of rows minus one (0..mysqli_num_rows() - 1).

返回值

成功时返回 true, 或者在失败时返回 false

范例

示例 #1 mysqli::data_seek() example

面向对象风格

<?php

mysqli_report
(MYSQLI_REPORT_ERROR MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost""my_user""my_password""world");

$query "SELECT Name, CountryCode FROM City ORDER BY Name";
$result $mysqli->query($query);

/* Seek to row no. 401 */
$result->data_seek(400);

/* Fetch single row */
$row $result->fetch_row();

printf("City: %s  Countrycode: %s\n"$row[0], $row[1]);

过程化风格

<?php

mysqli_report
(MYSQLI_REPORT_ERROR MYSQLI_REPORT_STRICT);
$link mysqli_connect("localhost""my_user""my_password""world");

$query "SELECT Name, CountryCode FROM City ORDER BY Name";

$result mysqli_query($link$query);

/* Seek to row no. 401 */
mysqli_data_seek($result400);

/* Fetch single row */
$row mysqli_fetch_row($result);

printf ("City: %s  Countrycode: %s\n"$row[0], $row[1]);

以上例程会输出:

City: Benin City  Countrycode: NGA

示例 #2 Adjusting the result pointer when iterating

This function can be useful when iterating over the result set to impose a custom order or rewind the result set when iterating multiple times.

<?php

mysqli_report
(MYSQLI_REPORT_ERROR MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost""my_user""my_password""world");

$query "SELECT Name, CountryCode FROM City ORDER BY Name LIMIT 15,4";
$result $mysqli->query($query);

/* Iterate the result set in reverse order */
for ($row_no $result->num_rows 1$row_no >= 0$row_no--) {
    
$result->data_seek($row_no);

    
/* Fetch single row */
    
$row $result->fetch_row();

    
printf("City: %s  Countrycode: %s\n"$row[0], $row[1]);
}

/* Reset pointer to the beginning of the result set */
$result->data_seek(0);

print 
"\n";

/* Iterate the same result set again */
while ($row $result->fetch_row()) {
    
printf("City: %s  Countrycode: %s\n"$row[0], $row[1]);
}

以上例程会输出:

City: Acmbaro  Countrycode: MEX
City: Abuja  Countrycode: NGA
City: Abu Dhabi  Countrycode: ARE
City: Abottabad  Countrycode: PAK

City: Abottabad  Countrycode: PAK
City: Abu Dhabi  Countrycode: ARE
City: Abuja  Countrycode: NGA
City: Acmbaro  Countrycode: MEX

注释

注意:

This function can only be used with buffered results attained from the use of the mysqli_store_result(), mysqli_query() or mysqli_stmt_get_result() functions.

参见

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