(PHP 8 >= 8.1.0)
mysqli_result::fetch_column -- mysqli_fetch_column — Fetch a single column from the next row of a result set
面向对象风格
$column = 0
) : null|int|float|string|false过程化风格
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 next row
within the result set, or false if there are no more rows.
Note: 此函数将 NULL 字段设置为 PHP
null值。
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。
column0-indexed number of the column you wish to retrieve from the row. If no value is supplied, the first column will be returned.
mysqli_fetch_column() returns a single column
from the next row of a result set or false if there are no more rows.
There is no way to return another column from the same row if you use this function to retrieve data.
Example #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