mysqli_result::fetch_column

mysqli_fetch_column

(PHP 8 >= 8.1.0)

mysqli_result::fetch_column -- mysqli_fetch_column — Fetch a single column from the next row of a result set

说明

面向对象风格

public mysqli_result::fetch_column(int $column = 0): null|int|float|string|false

过程化风格

mysqli_fetch_column(mysqli_result $result, int $column = 0): null|int|float|string|false

Fetches one row of data from the result set and returns the 0-indexed column. Each subsequent call to this function will return the value from the next row within the result set, or false if there are no more rows.

注意: 此函数将 NULL 字段设置为 PHP null 值。

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 mysqli_result 对象。

column

0-indexed number of the column you wish to retrieve from the row. If no value is supplied, the first column will be returned.

返回值

Returns a single column from the next row of a result set or false if there are no more rows.

警告

There is no way to return another column from the same row if you use this function to retrieve data.

范例

示例 #1 mysqli_result::fetch_column() 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 CountryCode, Name FROM City ORDER BY ID DESC LIMIT 5";

$result = $mysqli->query($query);

/* fetch a single value from the second column */
while ($Name = $result->fetch_column(1)) {
    printf("%s\n", $Name);
}

过程化风格

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = mysqli_connect("localhost", "my_user", "my_password", "world");

$query = "SELECT CountryCode, Name FROM City ORDER BY ID DESC LIMIT 5";

$result = mysqli_query($mysqli, $query);

/* fetch a single value from the second column */
while ($Name = mysqli_fetch_column($result, 1)) {
    printf("%s\n", $Name);
}

以上例程的输出类似于：

Rafah
Nablus
Jabaliya
Hebron
Khan Yunis

参见