mysqli_stmt::prepare

mysqli_stmt_prepare

(PHP 5, PHP 7, PHP 8)

mysqli_stmt::prepare -- mysqli_stmt_prepare — Prepares an SQL statement for execution

说明

面向对象风格

public mysqli_stmt::prepare(string $query): bool

过程化风格

mysqli_stmt_prepare(mysqli_stmt $statement, string $query): bool

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.

注意:
In the case where a statement is passed 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.

参数

statement

仅以过程化样式：由 mysqli_stmt_init() 返回的 mysqli_stmt 对象。

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.

注意:
The markers are legal only in certain places in SQL statements. For example, they are permitted 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 permitted for identifiers (such as table or column names).

返回值

成功时返回 true，或者在失败时返回 false。

错误／异常

If mysqli error reporting is enabled (MYSQLI_REPORT_ERROR) and the requested operation fails, a warning is generated. If, in addition, the mode is set to MYSQLI_REPORT_STRICT, a mysqli_sql_exception is thrown instead.

示例

示例 #1 mysqli_stmt::prepare() example

面向对象风格

<?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);

过程化风格

<?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);

以上示例会输出：

Amersfoort is in district Utrecht

参见

mysqli_stmt_init() - 初始化语句并返回用于 mysqli_stmt_prepare（调用）的对象
mysqli_stmt_execute() - Executes a prepared statement
mysqli_stmt_fetch() - Fetch results from a prepared statement into the bound variables
mysqli_stmt_bind_param() - Binds variables to a prepared statement as parameters
mysqli_stmt_bind_result() - Binds variables to a prepared statement for result storage
mysqli_stmt_get_result() - Gets a result set from a prepared statement as a mysqli_result object
mysqli_stmt_close() - Closes a prepared statement