mysqli_stmt::prepare
mysqli_stmt_prepare
(PHP 5, PHP 7, PHP 8)
mysqli_stmt::prepare -- mysqli_stmt_prepare — Prepares an SQL statement for execution
Beschreibung
Objektorientierter Stil
$query): boolProzeduraler Stil
Prepares a statement for execution. The query must consist of a single SQL statement.
The statement template can contain zero or more question mark
(?) parameter markers—also called placeholders.
The parameter markers must be bound to application variables using
mysqli_stmt_bind_param() before executing the statement.
Hinweis:
In the case where you pass a statement to mysqli_stmt_prepare() that is longer than
max_allowed_packetof 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:
mysqlndon Linux returns an error code of 1153. The error message meansgot a packet bigger than.max_allowed_packetbytes
mysqlndon Windows returns an error code 2006. This error message meansserver has gone away.
libmysqlclienton all platforms returns an error code 2006. This error message meansserver has gone away.
Parameter-Liste
-
statement -
Nur bei prozeduralem Aufruf: ein von mysqli_stmt_init() zurückgegebenes mysqli_stmt-Objekt.
-
query -
The query, as a string. It must consist of a single SQL statement.
The SQL statement may contain zero or more parameter markers represented by question mark (
?) characters at the appropriate positions.Hinweis:
The markers are legal only in certain places in SQL statements. For example, they are permitted in the
VALUES()list of anINSERTstatement (to specify column values for a row), or in a comparison with a column in aWHEREclause to specify a comparison value.However, they are not permitted for identifiers (such as table or column names), 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. Bei einem Fehler wird false zurückgegeben.
Beispiele
Beispiel #1 mysqli_stmt::prepare() example
Objektorientierter Stil
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
$city = "Amersfoort";
/* create a prepared statement */
$stmt = $mysqli->stmt_init();
$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);
Prozeduraler Stil
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
$city = "Amersfoort";
/* create a prepared statement */
$stmt = mysqli_stmt_init($link);
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);
Die obigen Bespiele erzeugen folgende Ausgabe:
Amersfoort is in district Utrecht
Siehe auch
- mysqli_stmt_init() - Initializes a statement and returns an object for use with mysqli_stmt_prepare
- mysqli_stmt_execute() - Executes a prepared statement
- mysqli_stmt_fetch() - Fetch results from a prepared statement into the bound variables
- mysqli_stmt_bind_param() - Bindet Variablen als Parameter an eine vorbereitete Anweisung (prepared statement)
- mysqli_stmt_bind_result() - Bindet Variablen an eine vorbereitete Anweisung (prepared statement), um das Ergebnis einer Abfrage abzulegen
- mysqli_stmt_get_result() - Gets a result set from a prepared statement as a mysqli_result object
- mysqli_stmt_close() - Schließt eine vorbereitete Anweisung (prepared statement)
