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