(PHP 5, PHP 7, PHP 8)
mysqli_stmt::$field_count -- mysqli_stmt_field_count — Returns the number of columns in the given statement
面向对象风格
过程化风格
Returns the number of columns in the prepared statement.
Returns an integer representing the number of columns.
示例 #1 面向对象风格
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
$code = 'FR';
$stmt = $mysqli->prepare("SELECT Name FROM Country WHERE Code=?");
$stmt->bind_param('s', $code);
$stmt->execute();
$row = $stmt->get_result()->fetch_row();
for ($i = 0; $i < $stmt->field_count; $i++) {
printf("Value of column number %d is %s", $i, $row[$i]);
}示例 #2 过程化风格
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = mysqli_connect("localhost", "my_user", "my_password", "world");
$code = 'FR';
$stmt = mysqli_prepare($mysqli, "SELECT Name FROM Country WHERE Code=?");
mysqli_stmt_bind_param($stmt, 's', $code);
mysqli_stmt_execute($stmt);
$result = mysqli_stmt_get_result($stmt);
$row = mysqli_fetch_row($result);
for ($i = 0; $i < mysqli_stmt_field_count($stmt); $i++) {
printf("Value of column number %d is %s", $i, $row[$i]);
}以上示例的输出类似于：
Value of column number 0 is France