mysqli_fetch

PHP Manual
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Description

Procedural style:

mixed mysqli_fetch_lengths ( object result)

Object oriented style (property):

class result {

mixed lengths

}

The mysqli_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 or FALSE on failure.

Return values

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

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

Example

例子 1. Object oriented style


<?php
$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 * from Country ORDER BY Code LIMIT 1";

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

    $row = $result->fetch_row();

    /* display column lengths */
    for ($i=0; $i < count($result->lengths); $i++) {
        printf("Field %2d has Length %2d\n", $i+1, $result->lengths[$i]);
    }
    $result->close();
}

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

例子 2. Procedural style


<?php
$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 * from Country ORDER BY Code LIMIT 1";

if ($result = mysqli_query($link, $query)) {

    $row = mysqli_fetch_row($result);

    /* display column lengths */
    $lengths = mysqli_fetch_lengths($result);
    for ($i=0; $i < count($lengths); $i++) {
        printf("Field %2d has Length %2d\n", $i+1, $lengths[$i]);
    }
    mysqli_free_result($result);
}

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

The above examples would produce the following output:

Field  1 has Length  3
Field  2 has Length  5
Field  3 has Length 13
Field  4 has Length  9
Field  5 has Length  6
Field  6 has Length  1
Field  7 has Length  6
Field  8 has Length  4
Field  9 has Length  6
Field 10 has Length  6
Field 11 has Length  5
Field 12 has Length 44
Field 13 has Length  7
Field 14 has Length  3
Field 15 has Length  2

后退	起点	前进
mysqli_fetch_fields	上一级	mysqli_fetch_object