mysqli::$field_count

mysqli_field_count

(PHP 5, PHP 7, PHP 8)

mysqli::$field_count -- mysqli_field_countReturns the number of columns for the most recent query

Descrizione

Stile orientato agli oggetti

Stile procedurale

mysqli_field_count(mysqli $mysql): int

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.

Elenco dei parametri

link

Solo nello stile procedurale: un identificatore restituito da mysqli_connect() o mysqli_init()

Valori restituiti

An integer representing the number of fields in a result set.

Esempi

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);
?>
add a note

User Contributed Notes 1 note

up
-30
dedlfix
17 years ago
There are MYSQLI_TYPE_* constants for the type property (listed in http://php.net/manual/en/ref.mysqli.php).

e.g.
<?php
if ($finfo->type == MYSQLI_TYPE_VAR_STRING)
// a VARCHAR
To Top