Copyright 1997-2022 the PHP Documentation Group.
mysqli_stmt::prepare
mysqli_stmt_prepare
Prepares an SQL statement for execution
Description
Object-oriented style
public bool mysqli_stmt::prepare(string query);
Procedural style
bool mysqli_stmt_prepare(mysqli_stmt statement,
string query);
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.
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 thanmax_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”.
Parameters
-
statement
Procedural style only: A
mysqli_stmt
object returned bymysqli_stmt_init
.-
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.NoteThe markers are legal only in certain places in SQL statements. For example, they are permitted in the
VALUES()
list of anINSERT
statement (to specify column values for a row), or in a comparison with a column in aWHERE
clause 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.
Return Values
Returns true
on success or
false
on failure.
Examples
Example 7.102 mysqli_stmt::prepare
example
Object-oriented style
<?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);
Procedural style
<?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);
The above examples will output:
Amersfoort is in district Utrecht
See Also
mysqli_stmt_init
|
mysqli_stmt_execute
|
mysqli_stmt_fetch
|
mysqli_stmt_bind_param
|
mysqli_stmt_bind_result
|
mysqli_stmt_get_result
|
mysqli_stmt_close
|