(PHP 5, PHP 7, PHP 8)
mysqli::$field_count -- mysqli_field_count — Returns the number of columns for the most recent query
Stile orientato agli oggetti
Stile procedurale
Returns the number of columns for the most recent query on the connection
represented by the mysql
parameter. This function
can be useful when using the mysqli_store_result()
function to determine if the query should have produced a non-empty result
set or not without knowing the nature of the query.
link
Solo nello stile procedurale: un identificatore restituito da mysqli_connect() o mysqli_init()
An integer representing the number of fields in a result set.
Example #1 $mysqli->field_count example
Stile orientato agli oggetti
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "test");
$mysqli->query( "DROP TABLE IF EXISTS friends");
$mysqli->query( "CREATE TABLE friends (id int, name varchar(20))");
$mysqli->query( "INSERT INTO friends VALUES (1,'Hartmut'), (2, 'Ulf')");
$mysqli->real_query("SELECT * FROM friends");
if ($mysqli->field_count) {
/* this was a select/show or describe query */
$result = $mysqli->store_result();
/* process resultset */
$row = $result->fetch_row();
/* free resultset */
$result->close();
}
/* close connection */
$mysqli->close();
?>
Stile procedurale
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "test");
mysqli_query($link, "DROP TABLE IF EXISTS friends");
mysqli_query($link, "CREATE TABLE friends (id int, name varchar(20))");
mysqli_query($link, "INSERT INTO friends VALUES (1,'Hartmut'), (2, 'Ulf')");
mysqli_real_query($link, "SELECT * FROM friends");
if (mysqli_field_count($link)) {
/* this was a select/show or describe query */
$result = mysqli_store_result($link);
/* process resultset */
$row = mysqli_fetch_row($result);
/* free resultset */
mysqli_free_result($result);
}
/* close connection */
mysqli_close($link);
?>