PHP-Handbuch: Prepare an SQL statement for execution

Beschreibung

Objektorientierter Stil

mixed mysqli_stmt::prepare ( string $query )

Prozeduraler Stil

bool mysqli_stmt_prepare ( mysqli_stmt $stmt , string $query )

Prepares the SQL query pointed to by the null-terminated string query.

The parameter markers must be bound to application variables using mysqli_stmt_bind_param and/or mysqli_stmt_bind_result before executing the statement or fetching rows.

Hinweis:
In the case where you pass a statement to mysqli_stmt_prepare that is longer than max_allowed_packet of the server, the returned error codes are different depending on whether you are using MySQL Native Driver (mysqlnd) or MySQL Client Library (libmysqlclient). The behavior is as follows:

mysqlnd on Linux returns an error code of 1153. The error message means got a packet bigger than max_allowed_packet bytes.

mysqlnd on Windows returns an error code 2006. This error message means server has gone away.

libmysqlclient on all platforms returns an error code 2006. This error message means server has gone away.

Parameter-Liste

stmt

Nur bei prozeduralem Aufruf: ein von mysqli_stmt_init zurückgegebenes Statementobjekt.

query

The query, as a string. It must consist of a single SQL statement.

You can include one or more parameter markers in the SQL statement by embedding question mark (?) characters at the appropriate positions.

Hinweis:
You should not add a terminating semicolon or \g to the statement.

Hinweis:
The markers are legal only in certain places in SQL statements. For example, they are allowed in the VALUES() list of an INSERT statement (to specify column values for a row), or in a comparison with a column in a WHERE clause to specify a comparison value.

However, they are not allowed for identifiers (such as table or column names), in the select list that names the columns to be returned by a SELECT statement), or to specify both operands of a binary operator such as the = equal sign. The latter restriction is necessary because it would be impossible to determine the parameter type. In general, parameters are legal only in Data Manipulation Language (DML) statements, and not in Data Definition Language (DDL) statements.

Rückgabewerte

Gibt bei Erfolg TRUE zurück. Im Fehlerfall wird FALSE zurückgegeben.

Beispiele

Beispiel #1 Objektorientierter Stil


<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

$city = "Amersfoort";

/* create a prepared statement */
$stmt =  $mysqli->stmt_init();
if ($stmt->prepare("SELECT District FROM City WHERE Name=?")) {

    /* bind parameters for markers */
    $stmt->bind_param("s", $city);

    /* execute query */
    $stmt->execute();

    /* bind result variables */
    $stmt->bind_result($district);

    /* fetch value */
    $stmt->fetch();

    printf("%s is in district %s\n", $city, $district);

    /* close statement */
    $stmt->close();
}

/* close connection */
$mysqli->close();
?>

Beispiel #2 Prozeduraler Stil


<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

$city = "Amersfoort";

/* create a prepared statement */
$stmt = mysqli_stmt_init($link);
if (mysqli_stmt_prepare($stmt, 'SELECT District FROM City WHERE Name=?')) {

    /* bind parameters for markers */
    mysqli_stmt_bind_param($stmt, "s", $city);

    /* execute query */
    mysqli_stmt_execute($stmt);

    /* bind result variables */
    mysqli_stmt_bind_result($stmt, $district);

    /* fetch value */
    mysqli_stmt_fetch($stmt);

    printf("%s is in district %s\n", $city, $district);

    /* close statement */
    mysqli_stmt_close($stmt);
}

/* close connection */
mysqli_close($link);
?>

Die obigen Bespiele erzeugen folgende Ausgabe:

Amersfoort is in district Utrecht

Siehe auch

mysqli_stmt_init
mysqli_stmt_execute
mysqli_stmt_fetch
mysqli_stmt_bind_param
mysqli_stmt_bind_result
mysqli_stmt_get_result
mysqli_stmt_close