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PHP - Manual: maxdb_fetch_lengths

2024-12-23

maxdb_fetch_lengths

maxdb_result::lengths

(PECL maxdb >= 1.0)

maxdb_fetch_lengths -- maxdb_result::lengthsReturns the lengths of the columns of the current row in the result set

说明

过程化风格

maxdb_fetch_lengths ( resource $result ) : array

面向对象风格

array $maxdb_result->lengths;

The maxdb_fetch_lengths() function returns an array containing the lengths of every column of the current row within the result set represented by the result parameter. If successful, a numerically indexed array representing the lengths of each column is returned 或者在失败时返回 FALSE.

返回值

An array of integers representing the size of each column (not including any terminating null characters). FALSE if an error occurred.

maxdb_fetch_lengths() is valid only for the current row of the result set. It returns FALSE if you call it before calling maxdb_fetch_row/array/resource or after retrieving all rows in the result.

范例

Example #1 面向对象风格

<?php
$maxdb 
= new maxdb("localhost""MONA""RED""DEMODB");

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

$query "SELECT * from hotel.customer WHERE cno = 3000";

if (
$result $maxdb->query($query)) {

   
$row $result->fetch_row();

   
/* display column lengths */
   
foreach ($result->lengths as $i => $val) {
       
printf("Field %2d has Length %2d\n"$i+1$val);
   }
   
$result->close();
}

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

Example #2 过程化风格

<?php
$link 
maxdb_connect("localhost""MONA""RED""DEMODB");

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

$query "SELECT * from hotel.customer WHERE cno = 3000";

if (
$result maxdb_query($link$query)) {

   
$row maxdb_fetch_row($result);

   
/* display column lengths */
   
foreach (maxdb_fetch_lengths($result) as $i => $val) {
       
printf("Field %2d has Length %2d\n"$i+1$val);
   }
   
maxdb_free_result($result);
}

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

以上例程的输出类似于:

Field  1 has Length  4
Field  2 has Length  3
Field  3 has Length  5
Field  4 has Length  6
Field  5 has Length  5
Field  6 has Length 21
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官方地址:https://www.php.net/manual/en/function.maxdb-fetch-lengths.php

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